Anti c-Met antibodies

ABSTRACT

The present invention relates to antibodies that specifically bind to the human c-Met receptor protein and that act as strict antagonists of hepatocyte growth factor (HGF)-mediated activation of the c-Met receptor and also inhibit HGF-independent activation of the human c-Met protein.

RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/098,849, filed Dec. 6, 2013, which is a division of U.S. patentapplication Ser. No. 13/288,566, filed Nov. 3, 2011, now U.S. Pat. No.8,637,027, which claims priority to U.S. Provisional Patent ApplicationSer. No. 61/409,866, filed Nov. 3, 2010. This application is alsorelated to PCT Patent Application No. PCT/EP2011/069369, filed Nov. 3,2011, and PCT Patent Application No. PCT/EP2011/069372. The contents ofthe aforementioned applications are hereby incorporated by reference intheir entirety.

TECHNICAL FIELD

The present invention relates to antibodies that specifically bind tothe human c-Met receptor protein and that act as strict antagonists ofhepatocyte growth factor (HGF)-mediated activation of the c-Met receptorand/or inhibit HGF-independent activation of the c-Met receptor.

BACKGROUND

The receptor tyrosine kinase, c-Met, and its ligand hepatocyte growthfactor (HGF) have become leading candidates for targeted cancertherapies.

c-Met is the cell surface receptor for hepatocyte growth factor (HGF),also known as scatter factor. The c-Met receptor is a disulfide-linkedheterodimer consisting of extracellular α and β chains. The α chain,heterodimerized to the amino-terminal portion of the β chain, forms themajor ligand-binding site in the extra cellular domain. HGF bindinginduces c-Met receptor homodimerization and phosphorylation of twotyrosine residues (Y1234 and Y1235) within the catalytic site,regulating kinase activity.

HGF-mediated activation of c-Met results in a complex genetic programmereferred to as “invasive growth”, consisting of a series ofphysiological processes, including proliferation, invasion, andangiogenesis, that occur under normal physiological conditions duringembryonic development and pathologically during oncogenesis. Signallingthrough c-Met promotes proliferation and cell survival through a varietyof downstream effectors.

In tumour cells, c-Met activation causes the triggering of a diverseseries of signalling cascades resulting in cell growth, proliferation,invasion and protection from apoptosis. The underlying biologicalmechanisms for tumorigenicity of c-Met are typically achieved in threedifferent ways: (a) with the establishment of HGF/c-Met autocrine loops;(b) via c-Met or HGF over-expression; and (c) in the presence ofkinase-activating mutations in the c-Met receptor coding sequence. HGFand c-Met expression has been observed in tumour biopsies of most solidtumours, and c-Met signalling has been documented in a wide range ofhuman malignancies, including bladder, breast, cervical, colorectal,gastric, head and neck, liver, lung, ovarian, pancreatic, prostrate,renal and thyroid cancers.

Activation of c-Met by its ligand, HGF, can occur in either a paracrineor an autocrine manner. Paracrine activation can become pathological inthe presence of abnormal HGF production. Autocrine activation occurswhen tumour cells aberrantly express both HGF and its receptor. Inaddition, c-Met activation can occur in an HGF-independent manner,mediated by c-Met homodimerization.

A wide variety of human malignancies exhibit sustained c-Metstimulation, over-expression or mutation, including carcinomas of thebreast, liver, lung, ovary, kidney and thyroid. Activating mutations inc-Met have been positively identified in patients with a particularhereditary form of papillary renal cancer, directly implicating c-Met inhuman tumorigenesis. Aberrant signalling of the c-Met signalling pathwaydue to disregulation of the c-Met receptor or over-expression of itsligand, HGF, has been associated with an aggressive phenotype. Extensiveevidence that c-Met signalling is involved in the progression and spreadof several cancers and an enhanced understanding of its role in diseasehave generated considerable interest in c-Met and HGF as major targetsin cancer drug development (Eder et al, Clin Cancer Research; 15(7);2009).

A variety of c-Met pathway antagonists with potential clinicalapplications are currently under clinical investigation. Potential c-Metantagonists include monoclonal antibodies which block the interaction ofc-Met with its ligand HGF. The most extensively described is theanti-c-Met 5D5 antibody generated by Genentech (WO96/38557). 5D5 behavesas a potent agonist when added alone in various models and as anantagonist when used as a Fab fragment or a one-armed antibody (MetMab).

WO 2009/007427 describes mouse monoclonal antibodies to c-Met andchimeric variants in which the antigen-binding domains of the mousemonoclonal antibody, or a humanised variant thereof, are coupled to theconstant region of human IgG1. However, whilst the original mousemonoclonal antibody, 224G11, exhibits antagonist activity withoutsignificant intrinsic agonist activity, coupling of the antigen bindingdomains of 224G11 to human IgG1 generated a chimeric form of 224G11which exhibited some agonist activity associated with a reducedantagonist efficacy. The agonist activity exhibited by the chimeric formof 224G11 can be reversed by engineering point mutations in the heavychain hinge domain of the human IgG1. In this engineered variant severalhuman amino residues in the hinge region are replaced by murine residuesoccurring at equivalent positions in the murine IgG1 sequence. C-Metreceptor antagonist activity is restored in the resulting engineeredvariant, but the overall structural and sequence homology to humanantibodies is reduced as a result of the mutations required in the hingeregion. In addition, at least one of the hypervariable loops in 224G11adopts a canonical structure which is not found in the human antibodyrepertoire.

WO 2007/126799 describes fully human monoclonal antibodies to c-Met.These antibodies behave as antagonists of the interaction with HGF, butno data is presented regarding the intrinsic agonist activity of theseantibodies or their ability to inhibit c-Met dimerization.

WO 2010/059654 also describes monoclonal c-Met antibodies. Theseantibodies are characterised by binding to the a-chain of human c-Metand inducing internalisation of cell surface human c-Met.

DESCRIPTION OF THE INVENTION

Provided herein is an isolated antibody, or an antigen binding fragmentthereof, that specifically binds to a human c-Met protein, wherein theantibody exhibits at least two or all three of the following properties:

(a) is a strict antagonist of HGF-mediated activation of the human c-Metprotein,

(b) inhibits HGF-independent activation of the human c-Met protein, and

(c) does not induce significant down-regulation of cell surface humanc-Met protein.

In one embodiment there is provided an isolated antibody, or an antigenbinding fragment thereof, that specifically binds to a human c-Metprotein, wherein the antibody exhibits the following properties:

(a) is a strict antagonist of HGF-mediated activation of the human c-Metprotein,

(b) inhibits HGF-independent activation of the human c-Met protein.

In one embodiment there is provided an isolated antibody, or an antigenbinding fragment thereof, that specifically binds to a human c-Metprotein, wherein the antibody exhibits the following properties:

(a) is a strict antagonist of HGF-mediated activation of the human c-Metprotein, and

(c) does not induce significant down-regulation of cell surface humanc-Met protein.

In one embodiment there is provided an isolated antibody, or an antigenbinding fragment thereof, that specifically binds to a human c-Metprotein, wherein the antibody exhibits the following properties:

(b) inhibits HGF-independent activation of the human c-Met protein, and

(c) does not induce significant down-regulation of cell surface humanc-Met protein.

In a further embodiment there is provided an isolated antibody, or anantigen binding fragment thereof, that specifically binds to a humanc-Met protein, wherein the antibody exhibits all of the followingproperties:

(a) is a strict antagonist of HGF-mediated activation of the human c-Metprotein,

(b) inhibits HGF-independent activation of the human c-Met protein, and

(c) does not induce significant down-regulation of cell surface humanc-Met protein.

In a particular embodiment the antibody or antigen binding fragment maybind to an epitope within the IPT region of the human c-Met protein, inparticular an epitope within IPT domains 1-2, 2-3 or 3-4 of the humanc-Met protein, or binds to an epitope within the PSI-IPT1 region of thehuman c-Met protein.

In a further embodiment the antibody or antigen binding fragment maybind to an epitope within the amino acid sequence₅₂₃-RSEECLSGTWTQQICLPAIYKVFPNSAPLEG GTRLTICGWDFGFRRNNKFDLKKTRVLLGNESCTLTLSESTMNTLKCTVGPAM NKHFNMSIIISNGHGTTQYSTFSYVDP-₆₃₃ (SEQ ID NO: 136) inthe PSI-IPT1 region of said human c-Met protein.

In a further embodiment the antibody or antigen binding fragment mayblock binding of HGF to the high affinity HGF binding site of the humanc-Met protein.

In a further embodiment there is provided an antibody or antigen bindingfragment thereof that:

(a) binds to an epitope within the SEMA domain of the human c-Metprotein

(b) does not induce down-regulation of cell surface human c-Met protein.

In an exemplary embodiment this antibody or antigen binding fragmentthereof binds to an epitope within the peptide98-VDTYYDDQLISCGSVNRGTCQRHVEPHNHTADIQSEVHCIFSPQIEEPSQCPDCVVSALGAKVESSVKDRFINFFVGNTINSSYFPDHPLHSISVRRLKETK-199 (SEQ ID NO: 181) in the SEMAdomain of human c-Met.

This antibody or antigen binding fragment may block binding of HGF tothe low affinity HGF binding site of human c-Met protein.

In any of the foregoing embodiments the antibody or antigen bindingfragment may comprise a hinge region having fully human sequence. Theantibody or antigen binding fragment may also have high human homology,as defined herein

In one embodiment there is provided an antibody having high humanhomology which specifically bind to a human c-Met receptor protein andthat antagonises HGF-mediated activation of the c-Met receptor.

In an embodiment there is provided an isolated antibody having highhuman homology which specifically binds to a human c-Met receptorprotein, wherein the antibody is a strict antagonist of HGF-mediatedactivation of the c-Met receptor and comprises a hinge region havingfully human sequence, wherein the presence of the human hinge regiondoes not adversely affect the antagonist activity of the antibody.

In a further embodiment there is provided an isolated antibody havinghigh human homology, or an antigen binding fragment thereof, whichspecifically binds to a human c-Met protein, wherein said antibody orantigen binding fragment blocks the binding of HGF to the high affinityHGF binding site of said human c-Met protein and is a strict antagonistof HGF-mediated activation of the c-Met receptor.

In a further embodiment there is provided an isolated antibody havinghigh human homology, or an antigen binding fragment thereof, thatspecifically binds to a human c-Met protein, wherein said antibody orantigen binding fragment binds to an epitope within the IPT region orthe PSI-IPT1 region of said human c-Met protein and is a strictantagonist of HGF-mediated activation of the c-Met receptor. In oneembodiment the antibody, or an antigen binding fragment thereof, bindsto an epitope within IPT domains 1-2, 2-3 or 3-4 of the human c-Metprotein.

In a further embodiment there is provided an isolated antibody, or anantigen binding fragment thereof, that specifically binds to a humanc-Met protein, wherein said antibody or antigen binding fragment bindsto an epitope within the peptide ₅₂₃-RSEECLSGTWTQQICLPAIYKVFPNSAPLEGGTRLTICGWDFGFRRNNKFDLKKTRVLLGNESCTLTLSESTMNTLKCTVGPAMNKHFNMSIIISNGHGTTQYSTFSYVDP-₆₃₃ (SEQ ID NO: 136) in thePSI-IPT1 region of human c-Met protein.

In an exemplary embodiment this antibody, or an antigen binding fragmentthereof, may be a strict antagonist of HGF-mediated activation of thehuman c-Met protein and may also inhibit HGF-independent activation ofthe human c-Met protein, and preferably does not induce significantdown-regulation of cell surface human c-Met protein.

In another embodiment, the antibody of an antigen binding fragmentthereof binds a conformational epitope comprising part of the IPTdomains in addition to part of another domain of c-Met, such as the SEMAdomain.

In each of the foregoing embodiments, the antibody may be any of, amonoclonal antibody, a fully human monoclonal antibody, or a humanisedmonoclonal antibody, each of which may exhibit bivalent binding to thehuman c-Met protein.

In a particular embodiment, the antibody having high human homology, orantigen binding fragment thereof, may comprise a heavy chain variabledomain (VH) and light chain variable domain (VL), wherein the VH and VLdomains, or one or more CDRs thereof, are camelid-derived.

In one embodiment there is provided an isolated antibody, or an antigenbinding fragment thereof, that specifically binds to a human c-Metprotein and is a strict antagonist of HGF-mediated activation of thec-Met receptor, which antibody or antigen binding fragment comprises aheavy chain variable domain (VH) and a light chain variable domain (VL),wherein the VH and VL domains, or one or more CDRs thereof, arecamelid-derived. In a particular embodiment the antibody, or antigenbinding fragment thereof, may comprise llama VH and VL domains, orhumanised llama VH and VL domains. This antibody, or antigen bindingfragment, may also exhibit “high human homology”, as defined herein.

In non-limiting embodiments the invention provides the followingantibodies, or antigen binding fragments thereof, which are defined byreference to specific structural characteristics, i.e. specified aminoacid sequences of either the CDRs (one or more of SEQ ID NOs: 1-21,71-73 or 83-85 (heavy chain CDRs) or SEQ ID NOs: 22-42, 74-76, 86, 87 or137-148 (light chain CDRs) or entire variable domains (one or more ofSEQ ID NOs: 45-58, 77, 78, 88, 89, 92-121 or 149-164). All of theseantibodies specifically bind to the human c-Met protein and are strictantagonists of HGF-mediated activation of the c-Met receptor. Inparticular embodiments, the antibodies defined by the followingstructural characteristics may additionally exhibit high human homology,as defined herein. The antibodies may be monoclonal antibodies producedby recombinant means. The CDRs of the following c-Met antibodies may becamelid-derived, i.e. derived from conventional antibodies raised byimmunisation of camelids (specifically llama) with c-Met antigen. Theinvention also provides humanised or human germlined variants, affinityvariants and variants containing conservative amino acid substitutions,as defined herein. Specifically provided are chimeric antibodiescontaining VH and VL domains which are camelid-derived, or humanised orgermlined variants thereof, fused to constant domains of humanantibodies, in particular human IgG1, IgG2, IgG3 or IgG4. These chimericantibodies may include a hinge region having fully human sequence, asdefined herein.

Exemplary embodiments of the c-Met antibodies are now further describedby reference to structural characteristics.

In one embodiment there is provided an isolated antibody or antigenbinding fragment thereof, wherein said antibody or antigen bindingfragment specifically binds human c-Met protein, said antibody orantigen binding fragment comprising a heavy chain variable domaincomprising a variable heavy chain CDR3 comprising a sequence selectedfrom the group consisting of:

SEQ ID NO:21 [DVRVIATGWATANALDA], or sequence variant thereof,

SEQ ID NO:15 [VDDYYLGYDY], or sequence variant thereof,

SEQ ID NO:3 [RRDNYYGTSGEYDY], or sequence variant thereof,

SEQ ID NO:6 [DTVVSGNGY], or sequence variant thereof,

SEQ ID NO:9 [DLIGSHDY], or sequence variant thereof,

SEQ ID NO:12 [GPGWYSGSRNDY], or sequence variant thereof,

SEQ ID NO:18 [LEDYELAYDY], or sequence variant thereof, and

SEQ ID NO:73 [SGYGSSLGDFGS] or sequence variant thereof,

wherein the sequence variant comprises one, two or three amino acidsubstitutions (e.g., conservative substitutions, humanisingsubstitutions or affinity variants) in the recited sequence.

The heavy chain variable domain of this antibody may further comprise avariable heavy chain CDR2 comprising a sequence selected from the groupconsisting of

SEQ ID NO: 195 (a) [X₁X₂X₃X₄X₅X₆X₇X₈ TYYAESMK]or sequence variant thereof, wherein

X1 is any amino acid, preferably T or A;

X2 is any amino acid, preferably I,

X3 is any amino acid, preferably S or N;

X4 is any amino acid, preferably W,

X5 is any amino acid, preferably N,

X6 is any amino acid, preferably D or G;

X7 is any amino acid, preferably I, G or S; and

X8 is any amino acid, preferably N or S;

SEQ ID NO: 196 (b) [VIAYDGSTX₁ YSPSLKS]or sequence variant thereof, wherein

X1 is any amino acid, preferably Y or D; and

SEQ ID NO: 197 (c) [RIDPEX₁ GGTKYAQKFQG],or sequence variant thereof, wherein,

X1 is any amino acid, preferably D, N or E; and

wherein the sequence variant comprises one, two or three amino acidsubstitutions (e.g., conservative substitutions, humanisingsubstitutions or affinity variants) in the recited sequence.

The heavy chain variable domain of this antibody may further comprise avariable heavy chain CDR1 comprising a sequence selected from the groupconsisting of:

(a) SEQ ID NO: 198 [X₁ DYX₂ MX₃], or sequence variant thereof, wherein

X₁ is any amino acid, preferably D or S,

X₂ is any amino acid, preferably A or V, and

X₃ is any amino acid, preferably T, N or S;

(b) SEQ ID NO:199 [X₁ NYYX₂ WS], or sequence variant thereof, wherein

X1 is any amino acid, preferably G or T, and

X2 is any amino acid, preferably A or Y;

(c) SEQ ID NO:200 [X₁X₂X₃ ID], or sequence variant thereof, wherein,

X1 is any amino acid, preferably M or N,

X2 is any amino acid, preferably N or Y, and

X3 is any amino acid, preferably S or V, and

wherein the sequence variant comprises one, two or three amino acidsubstitutions (e.g., conservative substitutions, humanisingsubstitutions or affinity variants) in the recited sequence.

The antibody or antigen binding fragment may further comprise a lightchain variable domain comprising a variable light chain CDR3 comprisingan amino acid sequence selected from the group consisting of:

(a) SEQ ID NO: 201 [QQGX₁SFPX₂ X ₃], or sequence variant thereof,wherein

X₁ is any amino acid, preferably Y or W;

X₂ is any amino acid, preferably Y or L;

X₃ is any amino acid, preferably T or S;

(b) SEQ ID NO:202 [ASYRX₁X₂X₃X₄X₅X₆ V], or sequence variant thereof,wherein

X1 is any amino acid, preferably S, I, R or T;

X2 is any amino acid, preferably A, S, T or R;

X3 is any amino acid, preferably N or T;

X4 is any amino acid, preferably N, D, R or K;

X5 is any amino acid, preferably A, V, Y, N or H;

X6 is any amino acid, preferably V, A, S or G.

wherein the sequence variant comprises one, two or three amino acidsubstitutions (e.g., conservative substitutions, humanisingsubstitutions or affinity variants) in the recited sequence.

The antibody or antigen binding fragment may further comprise a lightchain variable domain CDR2 comprising a sequence selected from the groupconsisting of:

(a) SEQ ID NO: 203 [WASX₁ RES], or sequence variant thereof, wherein

X1 is any amino acid, preferably I or T;

(b) SEQ ID NO:204 [X₁ VX₂X₃ RX₄ S], or sequence variant thereof, wherein

X1 is any amino acid, preferably D, A or E,

X2 is any amino acid, preferably N or S,

X3 is any amino acid, preferably R, Y or K,

X4 is any amino acid, preferably A, or P,

wherein the sequence variant comprises one, two or three amino acidsubstitutions (e.g., conservative substitutions, humanisingsubstitutions or affinity variants) in the recited sequence.

The antibody or antigen binding fragment may further comprise a lightchain variable domain CDR1 comprising a sequence selected from the groupconsisting of:

(a) SEQ ID NO: 205 [KSSQSVLX₁X₂ X₃ N X₄ K X₅ YLA], or sequence variantthereof, wherein

X1 is any amino acid, preferably W, L or F;

X2 is any amino acid, preferably R or S;

X3 is any amino acid, preferably S or P;

X4 is any amino acid, preferably Q or H;

X5 is any amino acid, preferably N or S

(b) SEQ ID NO:206 [X₁ GX₂X₃X₄X₅X₆ GX₇X₈X₉ YX₁₀ S], or sequence variantthereof, wherein

X1 is any amino acid, preferably A or T;

X2 is any amino acid, preferably T or S;

X3 is any amino acid, preferably S or N;

X4 is any amino acid, preferably S or T;

X5 is any amino acid, preferably D or N;

X6 is any amino acid, preferably V or I;

X7 is any amino acid, preferably Y, G, D or N;

X8 is any amino acid, preferably G or Y;

X9 is any amino acid, preferably N or Y;

X10 is any amino acid, preferably V or L

wherein the sequence variant comprises one, two or three amino acidsubstitutions (e.g., conservative substitutions, humanisingsubstitutions or affinity variants) in the recited sequence.

36C4, 20F1 and Variants Thereof

In one embodiment there is provided an isolated antibody or antigenbinding fragment thereof which specifically binds human c-Met protein,said antibody or antigen binding fragment comprising a heavy chainvariable domain wherein the variable heavy chain CDR3 sequence is SEQ IDNO:12 or SEQ ID NO:21 or sequence variant thereof, wherein the sequencevariant comprises one, two or three amino acid substitutions in therecited sequence.

In an embodiment of the antibody or antigen binding fragment thereof

the variable heavy chain CDR3 sequence is SEQ ID NO:21 or SEQ ID NO:12or sequence variant thereof;

the variable heavy chain CDR2 sequence is SEQ ID NO:196 or sequencevariant thereof; and

the variable heavy chain CDR1 sequence is SEQ ID NO:199 or sequencevariant thereof, and

wherein the sequence variant comprises one, two or three amino acidsubstitutions (e.g., conservative substitutions, humanisingsubstitutions or affinity variants) in the recited sequence.

In an embodiment of the antibody or antigen binding fragment thereof

the variable heavy chain CDR3 sequence is SEQ ID NO:21 or sequencevariant thereof;

the variable heavy chain CDR2 sequence is SEQ ID NO:20 or sequencevariant thereof or SEQ ID NO:83 or sequence variant thereof; and

the variable heavy chain CDR1 sequence is SEQ ID NO:19 or sequencevariant thereof, and

wherein the sequence variant comprises one, two or three amino acidsubstitutions (e.g., conservative substitutions, humanisingsubstitutions or affinity variants) in the recited sequence.

In an embodiment of the antibody or antigen binding fragment thereof

the variable heavy chain CDR3 sequence is SEQ ID NO:12 or sequencevariant thereof;

the variable heavy chain CDR2 sequence is SEQ ID NO:11 or sequencevariant thereof; and

the variable heavy chain CDR1 sequence is SEQ ID NO:10 or sequencevariant thereof, and

wherein the sequence variant comprises one, two or three amino acidsubstitutions (e.g., conservative substitutions, humanisingsubstitutions or affinity variants) in the recited sequence.

In an embodiment of the antibody or antigen binding fragment thereof

the variable light chain CDR3 sequence is SEQ ID NO:202 or sequencevariant thereof;

the variable light chain CDR2 sequence is SEQ ID NO:203 or sequencevariant thereof; and

the variable light chain CDR1 sequence is SEQ ID NO:206 or sequencevariant thereof, and

wherein the sequence variant comprises one, two or three amino acidsubstitutions in the recited sequence.

In an embodiment of the antibody or antigen binding fragment thereof

the variable light chain CDR3 sequence is selected from the groupconsisting of SEQ ID NO:33 or sequence variant thereof, SEQ ID NO:145 orsequence variant thereof, SEQ ID NO:146 or sequence variant thereof, SEQID NO:147 or sequence variant thereof, and SEQ ID NO:148 or sequencevariant thereof;

the variable light chain CDR2 sequence is SEQ ID NO:32 or sequencevariant thereof; and

the variable light chain CDR1 sequence is SEQ ID NO:31 or sequencevariant thereof, or SEQ ID NO:144 or sequence variant thereof, and

wherein the sequence variant comprises one, two or three amino acidsubstitutions (e.g., conservative substitutions, humanisingsubstitutions or affinity variants) in the recited sequence.

In an embodiment of the antibody or antigen binding fragment thereof

the variable light chain CDR3 sequence is SEQ ID NO:30 or sequencevariant thereof;

the variable light chain CDR2 sequence is SEQ ID NO:29 or sequencevariant thereof; and

the variable light chain CDR1 sequence is SEQ ID NO:28 or sequencevariant thereof, and

wherein the sequence variant comprises one, two or three amino acidsubstitutions (e.g., conservative substitutions, humanisingsubstitutions or affinity variants) in the recited sequence.

In a further embodiment there is provided an isolated monoclonalantibody or antigen binding fragment thereof, wherein said antibody orantigen binding fragment specifically binds human c-Met protein, saidantibody or antigen binding fragment comprising a heavy chain variabledomain and a light chain variable domain, wherein:

the variable heavy chain CDR3 sequence is SEQ ID NO:21 or sequencevariant thereof;

the variable heavy chain CDR2 sequence is selected from the groupconsisting of SEQ ID NO:20, SEQ ID NO:83 and SEQ ID NO:84 or sequencevariant thereof; and

the variable heavy chain CDR1 sequence is SEQ ID NO:19 or sequencevariant thereof; and the light chain variable domain includes acombination of CDRs selected from the following:

(i) the variable light chain CDR3 sequence is SEQ ID NO:33 or sequencevariant thereof;

the variable light chain CDR2 sequence is SEQ ID NO:32 or sequencevariant thereof;

the variable light chain CDR1 sequence is SEQ ID NO:31 or sequencevariant thereof,

wherein the sequence variant comprises one, two or three amino acidsubstitutions (e.g., conservative substitutions, humanisingsubstitutions or affinity variants) in the recited sequence; or

(ii) the variable light chain CDR3 sequence is SEQ ID NO:145 or sequencevariant thereof;

the variable light chain CDR2 sequence is SEQ ID NO:32 or sequencevariant thereof;

the variable light chain CDR1 sequence is SEQ ID NO:144 or sequencevariant thereof,

wherein the sequence variant comprises one, two or three amino acidsubstitutions (e.g., conservative substitutions, humanisingsubstitutions or affinity variants) in the recited sequence; or

(iii) the variable light chain CDR3 sequence is SEQ ID NO:146 orsequence variant thereof;

the variable light chain CDR2 sequence is SEQ ID NO:32 or sequencevariant thereof;

the variable light chain CDR1 sequence is SEQ ID NO:31 or sequencevariant thereof,

wherein the sequence variant comprises one, two or three amino acidsubstitutions (e.g., conservative substitutions, humanisingsubstitutions or affinity variants) in the recited sequence; or

(iv) the variable light chain CDR3 sequence is SEQ ID NO:147 or sequencevariant thereof;

the variable light chain CDR2 sequence is SEQ ID NO:32 or sequencevariant thereof;

the variable light chain CDR1 sequence is SEQ ID NO:144 or sequencevariant thereof,

wherein the sequence variant comprises one, two or three amino acidsubstitutions (e.g., conservative substitutions, humanisingsubstitutions or affinity variants) in the recited sequence; or

(v) the variable light chain CDR3 sequence is SEQ ID NO:148 or sequencevariant thereof;

the variable light chain CDR2 sequence is SEQ ID NO:32 or sequencevariant thereof;

the variable light chain CDR1 sequence is SEQ ID NO:144 or sequencevariant thereof,

wherein the sequence variant comprises one, two or three amino acidsubstitutions (e.g., conservative substitutions, humanisingsubstitutions or affinity variants) in the recited sequence.

In exemplary embodiments the antibody, or an antigen binding fragmentthereof, binds to an epitope within the peptide98-VDTYYDDQLISCGSVNRGTCQRHVFPHNHTADIQSEVHCIFSPQIEEPSQCPDCVVSALGAKVLSSVKDRFINFFVGNTINSSYFPDHPLHSISVRRLKETK-199 (SEQ ID NO: 181) in the SEMAdomain of human c-Met.

In an exemplary embodiment this antibody, or an antigen binding fragmentthereof, may be a strict antagonist of HGF-mediated activation of thehuman c-Met protein and may also inhibit HGF-independent activation ofthe human c-Met protein, and preferably does not induce significantdown-regulation of cell surface human c-Met protein.

In one embodiment this antibody may include the CH1 domain, hingeregion, CH2 domain and CH3 domain of a human antibody, in particularhuman IgG1, IgG2, IgG3 or IgG4.

In a further embodiment there is provided an isolated monoclonalantibody or antigen binding fragment thereof, wherein said antibody orantigen binding fragment specifically binds human c-Met protein, saidantibody or antigen binding fragment comprising a heavy chain variabledomain and a light chain variable domain, wherein:

the variable heavy chain CDR3 sequence is SEQ ID NO:12 or sequencevariant thereof;

the variable heavy chain CDR2 sequence is SEQ ID NO:11 or sequencevariant thereof; and

the variable heavy chain CDR1 sequence is SEQ ID NO:10 or sequencevariant thereof,

the variable light chain CDR3 sequence is SEQ ID NO:30 or sequencevariant thereof;

the variable light chain CDR2 sequence is SEQ ID NO:29 or sequencevariant thereof; and

the variable light chain CDR1 sequence is SEQ ID NO:28 or sequencevariant thereof, and

wherein the sequence variant comprises one, two or three amino acidsubstitutions (e.g., conservative substitutions, humanisingsubstitutions or affinity variants) in the recited sequence.

In an exemplary embodiment this antibody, or an antigen binding fragmentthereof, may be a strict antagonist of HGF-mediated activation of thehuman c-Met protein and may also inhibit HGF-independent activation ofthe human c-Met protein, and preferably does not induce significantdown-regulation of cell surface human c-Met protein.

In one embodiment this antibody may include the CH1 domain, hingeregion, CH2 domain and CH3 domain of a human antibody, in particularhuman IgG1, IgG2, IgG3 or IgG4.

In a further embodiment there is provided an isolated monoclonalantibody or antigen binding fragment thereof, wherein said antibody orantigen binding fragment specifically binds human c-Met protein, saidantibody or antigen binding fragment comprising a heavy chain variabledomain and a light chain variable domain, the heavy chain variabledomain comprising a VH sequence with at least 85% sequence identity, orat least 90% sequence identity, or at least 95% sequence identity, or atleast 97%, 98% or 99% sequence identity, to a sequence selected from thegroup consisting of: SEQ ID NO:51, 88, 92, 94, 96 and 98.

In a further embodiment there is provided an isolated monoclonalantibody or antigen binding fragment thereof, wherein said antibody orantigen binding fragment specifically binds human c-Met protein, saidantibody or antigen binding fragment comprising a heavy chain variabledomain and a light chain variable domain, the heavy chain variabledomain comprising a VH amino acid sequence selected from the groupconsisting of: SEQ ID NO: 51, 88, 92, 94, 96 and 98.

In a further embodiment there is provided an isolated monoclonalantibody or antigen binding fragment thereof, wherein said antibody orantigen binding fragment specifically binds human c-Met protein, saidantibody or antigen binding fragment comprising a heavy chain variabledomain and a light chain variable domain, the light chain variabledomain comprising a V Lambda sequence with at least 80% sequenceidentity, or at least 85% sequence identity, or at least 90% sequenceidentity, or at least 95% sequence identity, or at least 97%, 98% or 99%sequence identity, to an amino acid sequence selected from the groupconsisting of SEQ ID NO:55, 93, 95, 97, 99, 158, 159, 160, 161, 162, 163and 164.

In a further embodiment there is provided an isolated antibody orantigen binding fragment thereof, wherein said antibody or antigenbinding fragment specifically binds human c-Met protein, said antibodyor antigen binding fragment comprising a heavy chain variable domain anda light chain variable domain, the light chain variable domaincomprising a V Lambda amino acid sequence selected from the groupconsisting of SEQ ID NO:55, 93, 95, 97, 99, 158, 159, 160, 161, 162, 163and 164.

In a further embodiment there is provided an isolated antibody, or anantigen binding fragment thereof, that specifically binds to a humanc-Met protein and is preferably a strict antagonist of HGF-mediatedactivation of the c-Met receptor, the antibody or antigen-bindingfragment comprising a heavy chain variable domain and a light chainvariable domain, wherein the heavy chain variable domain comprises a VHsequence with at least 85% sequence identity, or at least 90% sequenceidentity, or at least 95% sequence identity, or at least 97%, 98% or 99%sequence identity to a sequence selected from the group consisting of:SEQ ID NO:51, 88, 92, 94, 96 and 98, and the light chain variable domaincomprises a V Lambda sequence with at least 80% sequence identity, or atleast 85% sequence identity, or at least 90% sequence identity, or atleast 95% sequence identity, or at least 97%, 98% or 99% sequenceidentity to an amino acid sequence selected from the group consisting ofSEQ ID NO:55, 93, 95, 97, 99, 158, 159, 160, 161, 162, 163 and 164.

In exemplary embodiments this antibody binds to an epitope within thepeptide98-VDTYYDDQLISCGSVNRGTCQRHVFPHNHTADIQSEVHCIFSPQIEEPSQCPDCVVSALGAKVLSSVKDRFINFFVGNTINSSYFPDHPLHSISVRRLKETK-199 (SEQ ID NO: 181) in the SEMAdomain of human c-Met.

In an exemplary embodiment this antibody, or an antigen binding fragmentthereof, may be a strict antagonist of HGF-mediated activation of thehuman c-Met protein and may also inhibit HGF-independent activation ofthe human c-Met protein, and preferably does not induce significantdown-regulation of cell surface human c-Met protein.

In one embodiment this antibody may include the CH1 domain, hingeregion, CH2 domain and CH3 domain of a human antibody, in particularhuman IgG1, IgG2, IgG3 or IgG4.

In a further embodiment there is provided an isolated antibody, or anantigen binding fragment thereof, that specifically binds to a humanc-Met protein and is preferably a strict antagonist of HGF-mediatedactivation of the c-Met receptor, the antibody comprising a heavy chainvariable domain (VH) comprising the amino acid sequence shown as SEQ IDNO:51 or SEQ ID NO:88 or a humanised or affinity variant thereof, and alight chain variable domain (VL) comprising the amino acid sequenceshown as SEQ ID NO:55, or a humanised, or affinity variant thereof.

In an exemplary embodiment this antibody, or an antigen binding fragmentthereof, may be a strict antagonist of HGF-mediated activation of thehuman c-Met protein and may also inhibit HGF-independent activation ofthe human c-Met protein, and preferably does not induce significantdown-regulation of cell surface human c-Met protein.

In one embodiment this antibody may include the CH1 domain, hingeregion, CH2 domain and CH3 domain of a human antibody, in particularhuman IgG1, IgG2, IgG3 or IgG4.

In a further embodiment there is provided an isolated antibody, or anantigen binding fragment thereof, that specifically binds to a humanc-Met protein and is preferably a strict antagonist of HGF-mediatedactivation of the c-Met receptor, the antibody or antigen-bindingfragment comprising a heavy chain variable domain and a light chainvariable domain, wherein the heavy chain variable domain comprises a VHsequence with at least 85% sequence identity, or at least 90% sequenceidentity, or at least 95% sequence identity, or at least 97%, 98% or 99%sequence identity the amino acid sequence shown as SEQ ID NO:51 or SEQID NO:88, and the light chain variable domain comprises a V Lambdasequence with at least 80% sequence identity, or at least 85% sequenceidentity, or at least 90% sequence identity, or at least 95% sequenceidentity, or at least 97%, 98% or 99% sequence identity to the aminoacid sequence shown as SEQ ID NO:55, or a humanised, or affinity variantthereof.

This antibody, or antigen-binding region may comprise heavy chain CDRswhich are identical to CDR1, CDR2 and CDR3 of SEQ ID NO:51 or to CDR1,CDR2 and CDR3 of SEQ ID NO:88 and light chain CDRs which are identicalto CDR1, CDR2 and CDR3 of SEQ ID NO:55, whilst exhibiting amino acidsequence variation within the framework regions.

In exemplary embodiments this antibody or antigen binding fragment bindsto an epitope within the peptide98-VDTYYDDQLISCGSVNRGTCQRHVFPHNHTADIQSEVHCIFSPQIEEPSQCPDCVVSALGAKVLSSVKDRFINFFVGNTINSSYFPDHPLHSISVRRLKETK-199 (SEQ IDNO: 181) in the SEMA domain of human c-Met.

In an exemplary embodiment this antibody, or an antigen binding fragmentthereof, may be a strict antagonist of HGF-mediated activation of thehuman c-Met protein and may also inhibit HGF-independent activation ofthe human c-Met protein, and preferably does not induce significantdown-regulation of cell surface human c-Met protein.

In one embodiment this antibody may include the CH1 domain, hingeregion, CH2 domain and CH3 domain of a human antibody, in particularhuman IgG1, IgG2, IgG3 or IgG4.

In a further embodiment there is provided an isolated antibody or anantigen binding fragment thereof that specifically binds to a humanc-Met protein and is preferably a strict antagonist of HGF-mediatedactivation of the c-Met receptor, which antibody is a human germlinedvariant of the antibody 36C4, said germlined variant antibodycomprising:—

(a) a heavy chain variable domain (VH) comprising the amino acidsequence shown as SEQ ID NO:92, and a light chain variable domain (VL)comprising the amino acid sequence shown as SEQ ID NO:93; or

(b) a heavy chain variable domain (VH) comprising the amino acidsequence shown as SEQ ID NO:94, and a light chain variable domain (VL)comprising the amino acid sequence shown as SEQ ID NO:95; or

(c) a heavy chain variable domain (VH) comprising the amino acidsequence shown as SEQ ID NO:96, and a light chain variable domain (VL)comprising the amino acid sequence shown as SEQ ID NO:97; or

(d) a heavy chain variable domain (VH) comprising the amino acidsequence shown as SEQ ID NO:98, and a light chain variable domain (VL)comprising the amino acid sequence shown as SEQ ID NO:99; or

(e) a heavy chain variable domain (VH) comprising the amino acidsequence shown as SEQ ID NO:88, and a light chain variable domain (VL)comprising an amino acid sequence selected from the group consisting ofSEQ ID NO:156, SEQ ID NO:157, SEQ ID NO:158, SEQ ID NO:159, SEQ IDNO:160, SEQ ID NO:161, SEQ ID NO:162, SEQ ID NO:163 and SEQ ID NO:164.

These variant 36C4 antibodies, or antigen-binding regions, areidentified as comprising a combination of a VH domain, defined byreference to a specific amino acid sequence, and a VL domain (V Kappa),also defined by reference to a specific amino acid sequence. For eachspecific VH/VL combination listed, this definition should be taken toinclude antibodies, or antigen binding regions, formed by combination ofa VH domain having at least 85%, at least 90%, at least 95%, at least97%, or at least 99% sequence identity to the stated VH amino acidsequence and a VL domain having at least 75%, at least 80%, at least85%, at least 90%, at least 95%, at least 97%, or at least 99% sequenceidentity to the stated VL amino acid sequence. In each case the VH andVL domains defined by % sequence identity to the stated VH and VL aminoacid sequences may retain identical CDR sequences to those present inthe stated VH and VL amino acid sequences, whilst exhibiting amino acidsequence variation within the framework regions.

In exemplary embodiments this antibody or antigen binding fragment bindsto an epitope within the peptide98-VDTYYDDQLISCGSVNRGTCQRHVFPHNHTADIQSEVHCIFSPQIEEPSQCPDCVVSALGAKVLSSVKDRFINFFVGNTINSSYFPDHPLHSISVRRLKETK-199 (SEQ IDNO: 181) in the SEMA domain of human c-Met.

In an exemplary embodiment this antibody, or an antigen binding fragmentthereof, may be a strict antagonist of HGF-mediated activation of thehuman c-Met protein and may also inhibit HGF-independent activation ofthe human c-Met protein, and preferably does not induce significantdown-regulation of cell surface human c-Met protein.

In one embodiment this antibody may include the CH1 domain, hingeregion, CH2 domain and CH3 domain of a human antibody, in particularhuman IgG1, IgG2, IgG3 or IgG4.

In a further embodiment there is provided an isolated antibody, or anantigen binding fragment thereof, that specifically binds to a humanc-Met protein and is preferably a strict antagonist of HGF-mediatedactivation of the c-Met receptor, which antibody is an affinity variantof 36C4Q, said affinity variant comprising a heavy chain variable domain(VH) comprising the amino acid sequence shown as SEQ ID NO:88, and alight chain variable domain (VL) comprising an amino acid sequenceselected from the group consisting of SEQ ID NO:156, SEQ ID NO:157, SEQID NO:158, SEQ ID NO:159, SEQ ID NO:160, SEQ ID NO:161, SEQ ID NO:162,SEQ ID NO:163 and SEQ ID NO:164.

In an exemplary embodiment this antibody, or an antigen binding fragmentthereof, may be a strict antagonist of HGF-mediated activation of thehuman c-Met protein and may also inhibit HGF-independent activation ofthe human c-Met protein, and preferably does not induce significantdown-regulation of cell surface human c-Met protein.

In one embodiment this antibody may include the CH1 domain, hingeregion, CH2 domain and CH3 domain of a human antibody, in particularhuman IgG1, IgG2, IgG3 or IgG4.

In a further embodiment there is provided an isolated monoclonalantibody or antigen binding fragment thereof, wherein said antibody orantigen binding fragment specifically binds human c-Met protein, saidantibody or antigen binding fragment comprising a heavy chain variabledomain and a light chain variable domain, the heavy chain variabledomain comprising a VH sequence with at least 85% sequence identity, orat least 90% sequence identity, or at least 95% sequence identity, or atleast 97%, 98% or 99% sequence identity, to the sequence shown as SEQ IDNO:48.

In a further embodiment there is provided an isolated monoclonalantibody or antigen binding fragment thereof, wherein said antibody orantigen binding fragment specifically binds human c-Met protein, saidantibody or antigen binding fragment comprising a heavy chain variabledomain and a light chain variable domain, the heavy chain variabledomain comprising the VH amino acid sequence shown as SEQ ID NO:48.

In a further embodiment there is provided an isolated monoclonalantibody or antigen binding fragment thereof, wherein said antibody orantigen binding fragment specifically binds human c-Met protein, saidantibody or antigen binding fragment comprising a heavy chain variabledomain and a light chain variable domain, the light chain variabledomain comprising a V Lambda sequence with at least 80% sequenceidentity, or at least 85% sequence identity, or at least 90% sequenceidentity, or at least 95% sequence identity, or at least 97%, 98% or 99%sequence identity, to the sequence shown as SEQ ID NO:54.

In a further embodiment there is provided an isolated antibody orantigen binding fragment thereof, wherein said antibody or antigenbinding fragment specifically binds human c-Met protein, said antibodyor antigen binding fragment comprising a heavy chain variable domain anda light chain variable domain, the light chain variable domaincomprising the V Lambda amino acid sequence shown as SEQ ID NO:48.

In a further embodiment there is provided an isolated antibody, or anantigen binding fragment thereof, that specifically binds to a humanc-Met protein and is preferably a strict antagonist of HGF-mediatedactivation of the c-Met receptor, the antibody comprising a heavy chainvariable domain (VH) comprising the amino acid sequence shown as SEQ IDNO:48, or a humanised or affinity variant thereof, and a light chainvariable domain (VL) comprising the amino acid sequence shown as SEQ IDNO:54, or a humanised, or affinity variant thereof.

In one embodiment this antibody may include the CH1 domain, hingeregion, CH2 domain and CH3 domain of a human antibody, in particularhuman IgG1, IgG2, IgG3 or IgG4.

48A2, 38H10, 40B8 and Variants Thereof

In a further embodiment there is provided an isolated antibody orantigen binding fragment thereof which specifically binds human c-Metprotein, said antibody or antigen binding fragment comprising a heavychain variable domain wherein the variable heavy chain CDR3 sequence isSEQ ID NO:15 or SEQ ID NO:18 or sequence variant thereof, wherein thesequence variant comprises one, two or three amino acid substitutions(e.g., conservative substitutions, humanising substitutions or affinityvariants) in the recited sequence.

In an embodiment of the antibody or antigen binding fragment thereof

the variable heavy chain CDR3 sequence is SEQ ID NO:15 or SEQ ID NO:18or sequence variant thereof;

the variable heavy chain CDR2 sequence is SEQ ID NO:197 or sequencevariant thereof; and

the variable heavy chain CDR1 sequence is SEQ ID NO:200 or sequencevariant thereof, and

wherein the sequence variant comprises one, two or three amino acidsubstitutions (e.g., conservative substitutions, humanisingsubstitutions or affinity variants) in the recited sequence.

In an embodiment of the antibody or antigen binding fragment thereof

the variable heavy chain CDR3 sequence is SEQ ID NO:15 or sequencevariant thereof;

the variable heavy chain CDR2 sequence is SEQ ID NO:14 or sequencevariant thereof or SEQ ID NO:85 or sequence variant thereof; and

the variable heavy chain CDR1 sequence is SEQ ID NO:13 or sequencevariant thereof, and

wherein the sequence variant comprises one, two or three amino acidsubstitutions (e.g., conservative substitutions, humanisingsubstitutions or affinity variants) in the recited sequence.

In an embodiment of the antibody or antigen binding fragment thereof

the variable heavy chain CDR3 sequence is SEQ ID NO:18 or sequencevariant thereof;

the variable heavy chain CDR2 sequence is SEQ ID NO:17 or sequencevariant thereof; and

the variable heavy chain CDR1 sequence is SEQ ID NO:16 or sequencevariant thereof, and

wherein the sequence variant comprises one, two or three amino acidsubstitutions (e.g., conservative substitutions, humanisingsubstitutions or affinity variants) in the recited sequence.

In one embodiment the antibody or antigen binding fragment thereoffurther comprises a light chain variable domain, wherein

the variable light chain CDR3 sequence is SEQ ID NO:201 or sequencevariant thereof;

the variable light chain CDR2 sequence is SEQ ID NO:203 or sequencevariant thereof; and

the variable light chain CDR1 sequence is SEQ ID NO:205 or sequencevariant thereof, and

wherein the sequence variant comprises one, two or three amino acidsubstitutions (e.g., conservative substitutions, humanisingsubstitutions or affinity variants) in the recited sequence.

In an embodiment of the antibody or antigen binding fragment thereof

the variable light chain CDR3 sequence is selected from the groupconsisting of SEQ ID NO:87 or sequence variant thereof, SEQ ID NO:139 orsequence variant thereof, and SEQ ID NO:141 or sequence variant thereof;

the variable light chain CDR2 sequence is SEQ ID NO:23 or sequencevariant thereof or SEQ ID NO:26 or sequence variant thereof; and

the variable light chain CDR1 sequence is selected from the groupconsisting of SEQ ID NO:86 or sequence variant thereof, SEQ ID NO:137 orsequence variant thereof, SEQ ID NO:138 or sequence variant thereof, SEQID NO:140 or sequence variant thereof, SEQ ID NO:142 or sequence variantthereof, and SEQ ID NO:143 or sequence variant thereof, and

wherein the sequence variant comprises one, two or three amino acidsubstitutions (e.g., conservative substitutions, humanisingsubstitutions or affinity variants) in the recited sequence.

In an embodiment of the antibody or antigen binding fragment thereof

the variable light chain CDR3 sequence is SEQ ID NO:24 or sequencevariant thereof;

the variable light chain CDR2 sequence is SEQ ID NO:23 or sequencevariant thereof; and

the variable light chain CDR1 sequence is SEQ ID NO:22 or sequencevariant thereof, and

wherein the sequence variant comprises one, two or three amino acidsubstitutions (e.g., conservative substitutions, humanisingsubstitutions or affinity variants) in the recited sequence.

In an embodiment of the antibody or antigen binding fragment thereof

the variable light chain CDR3 sequence is SEQ ID NO:27 or sequencevariant thereof;

the variable light chain CDR2 sequence is SEQ ID NO:26 or sequencevariant thereof; and

the variable light chain CDR1 sequence is SEQ ID NO:25 or sequencevariant thereof, and

wherein the sequence variant comprises one, two or three amino acidsubstitutions (e.g., conservative substitutions, humanisingsubstitutions or affinity variants) in the recited sequence.

In a further embodiment there is provided an isolated monoclonalantibody or antigen binding fragment thereof, wherein said antibody orantigen binding fragment specifically binds human c-Met protein, saidantibody or antigen binding fragment comprising a heavy chain variabledomain and a light chain variable domain, wherein:

the variable heavy chain CDR3 sequence is SEQ ID NO:15 or sequencevariant thereof;

the variable heavy chain CDR2 sequence is SEQ ID NO:14 or sequencevariant thereof; and

the variable heavy chain CDR1 sequence is SEQ ID NO:13 or sequencevariant thereof,

the variable light chain CDR3 sequence is SEQ ID NO:87 or sequencevariant thereof;

the variable light chain CDR2 sequence is SEQ ID NO:23 or sequencevariant thereof; and

the variable light chain CDR1 sequence is SEQ ID NO:86 or sequencevariant thereof, and

wherein the sequence variant comprises one, two or three amino acidsubstitutions (e.g., conservative substitutions, humanisingsubstitutions or affinity variants) in the recited sequence.

In an exemplary embodiment this antibody or antigen binding fragmentthereof binds to an epitope within the peptide₅₂₃-RSEECLSGTWTQQICLPAIYKVFPNSAPLEGGTRLTICGWDFGFRRNNKFDLKKTRVLLGNESCTLTLSESTMNTLKCTVGPAMNKHFNMSIIISNGHGTTQYSTFSYVDP-₆₃₃ (SEQ ID NO: 136) in the PSI-IPT1 regionof human c-Met protein.

In an exemplary embodiment this antibody, or an antigen binding fragmentthereof, may be a strict antagonist of HGF-mediated activation of thehuman c-Met protein and may also inhibit HGF-independent activation ofthe human c-Met protein, and preferably does not induce significantdown-regulation of cell surface human c-Met protein.

In one embodiment this antibody may include the CH1 domain, hingeregion, CH2 domain and CH3 domain of a human antibody, in particularhuman IgG1, IgG2, IgG3 or IgG4.

In a further embodiment there is provided an isolated monoclonalantibody or antigen binding fragment thereof, wherein said antibody orantigen binding fragment specifically binds human c-Met protein, saidantibody or antigen binding fragment comprising a heavy chain variabledomain and a light chain variable domain, wherein:

the variable heavy chain CDR3 sequence is SEQ ID NO:15 or sequencevariant thereof;

the variable heavy chain CDR2 sequence is SEQ ID NO:14 or sequencevariant thereof; and

the variable heavy chain CDR1 sequence is SEQ ID NO:13 or sequencevariant thereof; and the light chain variable domain includes acombination of CDRs selected from the following:

(i) the variable light chain CDR3 sequence is SEQ ID NO:24 or sequencevariant thereof;

the variable light chain CDR2 sequence is SEQ ID NO:23 or sequencevariant thereof; and

the variable light chain CDR1 sequence is SEQ ID NO:22 or sequencevariant thereof, and

wherein the sequence variant comprises one, two or three amino acidsubstitutions (e.g., conservative substitutions, humanisingsubstitutions or affinity variants) in the recited sequence; or

(ii) the variable light chain CDR3 sequence is SEQ ID NO:87 or sequencevariant thereof;

the variable light chain CDR2 sequence is SEQ ID NO:26 or sequencevariant thereof; and

the variable light chain CDR1 sequence is SEQ ID NO:137 or sequencevariant thereof, and

wherein the sequence variant comprises one, two or three amino acidsubstitutions (e.g., conservative substitutions, humanisingsubstitutions or affinity variants) in the recited sequence; or

(iii) the variable light chain CDR3 sequence is SEQ ID NO:139 orsequence variant thereof;

the variable light chain CDR2 sequence is SEQ ID NO:26 or sequencevariant thereof; and

the variable light chain CDR1 sequence is SEQ ID NO:138 or sequencevariant thereof, and

wherein the sequence variant comprises one, two or three amino acidsubstitutions (e.g., conservative substitutions, humanisingsubstitutions or affinity variants) in the recited sequence; or

(iv) the variable light chain CDR3 sequence is SEQ ID NO:141 or sequencevariant thereof;

the variable light chain CDR2 sequence is SEQ ID NO:26 or sequencevariant thereof; and

the variable light chain CDR1 sequence is SEQ ID NO:140 or sequencevariant thereof, and

wherein the sequence variant comprises one, two or three amino acidsubstitutions (e.g., conservative substitutions, humanisingsubstitutions or affinity variants) in the recited sequence; or

(v) the variable light chain CDR3 sequence is SEQ ID NO:141 or sequencevariant thereof;

the variable light chain CDR2 sequence is SEQ ID NO:26 or sequencevariant thereof; and

the variable light chain CDR1 sequence is SEQ ID NO:142 or sequencevariant thereof, and

wherein the sequence variant comprises one, two or three amino acidsubstitutions (e.g., conservative substitutions, humanisingsubstitutions or affinity variants) in the recited sequence; or

(vi) the variable light chain CDR3 sequence is SEQ ID NO:87 or sequencevariant thereof;

the variable light chain CDR2 sequence is SEQ ID NO:26 or sequencevariant thereof; and

the variable light chain CDR1 sequence is SEQ ID NO:86 or sequencevariant thereof, and

wherein the sequence variant comprises one, two or three amino acidsubstitutions (e.g., conservative substitutions, humanisingsubstitutions or affinity variants) in the recited sequence; or

(vii) the variable light chain CDR3 sequence is SEQ ID NO:87 or sequencevariant thereof;

the variable light chain CDR2 sequence is SEQ ID NO:26 or sequencevariant thereof; and

the variable light chain CDR1 sequence is SEQ ID NO:143 or sequencevariant thereof, and

wherein the sequence variant comprises one, two or three amino acidsubstitutions (e.g., conservative substitutions, humanisingsubstitutions or affinity variants) in the recited sequence.

In an exemplary embodiment this antibody or antigen binding fragmentthereof binds to an epitope within the peptide₅₂₃-RSEECLSGTWTQQICLPAIYKVFPNSAPLEGGTRLTICGWDFGFRRNNKFDLKKTRVLLGNESCTLTLSESTMNTLKCTVGPAMNKHFNMSIIISNGHGTTQYSTFSYVDP-₆₃₃ (SEQ ID NO: 136) in the PSI-IPT1 regionof human c-Met protein.

In an exemplary embodiment this antibody, or an antigen binding fragmentthereof, may be a strict antagonist of HGF-mediated activation of thehuman c-Met protein and may also inhibit HGF-independent activation ofthe human c-Met protein, and preferably does not induce significantdown-regulation of cell surface human c-Met protein.

In one embodiment this antibody may include the CH1 domain, hingeregion, CH2 domain and CH3 domain of a human antibody, in particularhuman IgG1, IgG2, IgG3 or IgG4.

In a further embodiment there is provided an isolated monoclonalantibody or antigen binding fragment thereof, wherein said antibody orantigen binding fragment specifically binds human c-Met protein, saidantibody or antigen binding fragment comprising a heavy chain variabledomain and a light chain variable domain the variable heavy chain CDR3sequence is SEQ ID NO:18 or sequence variant thereof;

the variable heavy chain CDR2 sequence is SEQ ID NO:17 or sequencevariant thereof; and

the variable heavy chain CDR1 sequence is SEQ ID NO:16 or sequencevariant thereof,

the variable light chain CDR3 sequence is SEQ ID NO:27 or sequencevariant thereof;

the variable light chain CDR2 sequence is SEQ ID NO:26 or sequencevariant thereof; and

the variable light chain CDR1 sequence is SEQ ID NO:25 or sequencevariant thereof, and

wherein the sequence variant comprises one, two or three amino acidsubstitutions (e.g., conservative substitutions, humanisingsubstitutions or affinity variants) in the recited sequence.

In an exemplary embodiment this antibody or antigen binding fragmentthereof binds to an epitope within the peptide₅₂₃-RSEECLSGTWTQQICLPAIYKVFPNSAPLEGGTRLTICGWDFGFRRNNKFDLKKTRVLLGNESCTLTLSESTMNTLKCTVGPAMNKHFNMSIIISNGHGTTQYSTFSYVDP-₆₃₃ (SEQ ID NO: 136) in the PSI-IPT1 regionof human c-Met protein.

In an exemplary embodiment this antibody, or an antigen binding fragmentthereof, may be a strict antagonist of HGF-mediated activation of thehuman c-Met protein and may also inhibit HGF-independent activation ofthe human c-Met protein, and preferably does not induce significantdown-regulation of cell surface human c-Met protein.

In one embodiment this antibody may include the CH1 domain, hingeregion, CH2 domain and CH3 domain of a human antibody, in particularhuman IgG1, IgG2, IgG3 or IgG4.

In a further embodiment there is provided an isolated monoclonalantibody or antigen binding fragment thereof, wherein said antibody orantigen binding fragment specifically binds human c-Met protein, saidantibody or antigen binding fragment comprising a heavy chain variabledomain and a light chain variable domain, the heavy chain variabledomain comprising a VH sequence with at least 85% sequence identity, orat least 90% sequence identity, or at least 95% sequence identity, or atleast 97%, 98% or 99% sequence identity, to an amino acid sequenceselected from the group consisting of: SEQ ID NO:49, 108, 110, 112, 114,116, 118 and 120.

In a further embodiment there is provided an isolated monoclonalantibody or antigen binding fragment thereof, wherein said antibody orantigen binding fragment specifically binds human c-Met protein, saidantibody or antigen binding fragment comprising a heavy chain variabledomain and a light chain variable domain, the heavy chain variabledomain comprising a VH amino acid sequence selected from the groupconsisting of: SEQ ID NO: 49, 108, 110, 112, 114, 116, 118 and 120.

In a further embodiment there is provided an isolated monoclonalantibody or antigen binding fragment thereof, wherein said antibody orantigen binding fragment specifically binds human c-Met protein, saidantibody or antigen binding fragment comprising a heavy chain variabledomain and a light chain variable domain, the light chain variabledomain comprising a V Kappa sequence with at least 75% sequenceidentity, or at least 80% sequence identity, or at least 85% sequenceidentity, or at least 90% sequence identity, or at least 95% sequenceidentity, or at least 97%, 98% or 99% sequence identity, to an aminoacid sequence selected from the group consisting of SEQ ID NO:52, 89,109, 111, 113, 115, 117, 119, 121, 149, 150, 151, 152, 153, 154, 155,156 and 157.

In a further embodiment there is provided an isolated antibody orantigen binding fragment thereof, wherein said antibody or antigenbinding fragment specifically binds human c-Met protein, said antibodyor antigen binding fragment comprising a heavy chain variable domain anda light chain variable domain, the light chain variable domaincomprising a VL amino acid sequence selected from the group consistingof SEQ ID NO:52, 89, 109, 111, 113, 115, 117, 119, 121, 149, 150, 151,152, 153, 154, 155, 156 and 157.

In a further embodiment there is provided an isolated monoclonalantibody or antigen binding fragment thereof, wherein said antibody orantigen binding fragment specifically binds human c-Met protein, theantibody or antigen-binding fragment comprising a heavy chain variabledomain and a light chain variable domain, the heavy chain variabledomain comprising a VH sequence with at least 85% sequence identity, orat least 90% sequence identity, or at least 95% sequence identity, or atleast 97%, 98% or 99% sequence identity to an amino acid sequenceselected from the group consisting of: SEQ ID NO:49, 108, 110, 112, 114,116, 118 and 120 and the light chain variable domain comprising a VKappa sequence with at least 75% sequence identity, or at least 80%sequence identity, or at least 85% sequence identity, or at least 90%sequence identity, or at least 95% sequence identity, or at least 97%,98% or 99% sequence identity to an amino acid sequence selected from thegroup consisting of SEQ ID NO:52, 89, 109, 111, 113, 115, 117, 119, 121,149, 150, 151, 152, 153, 154, 155, 156 and 157.

In an exemplary embodiment this antibody or antigen binding fragmentthereof binds to an epitope within the peptide₅₂₃-RSEECLSGTWTQQICLPAIYKVFPNSAPLEGGTRLTICGWDFGFRRNNKFDLKKTRVLLGNESCTLTLSESTMNTLKCTVGPAMNKHFNMSIIISNGHGTTQYSTFSYVDP-₆₃₃ (SEQ ID NO: 136) in the PSI-IPT1 regionof human c-Met protein.

In an exemplary embodiment this antibody, or an antigen binding fragmentthereof, may be a strict antagonist of HGF-mediated activation of thehuman c-Met protein and may also inhibit HGF-independent activation ofthe human c-Met protein, and preferably does not induce significantdown-regulation of cell surface human c-Met protein.

In one embodiment this antibody may include the CH1 domain, hingeregion, CH2 domain and CH3 domain of a human antibody, in particularhuman IgG1, IgG2, IgG3 or IgG4.

In a further embodiment there is provided an isolated monoclonalantibody or antigen binding fragment thereof, wherein said antibody orantigen binding fragment specifically binds human c-Met protein, theantibody or antigen-binding fragment comprising a heavy chain variabledomain comprising a VH sequence with at least 85% sequence identity, orat least 90% sequence identity, or at least 95% sequence identity, or atleast 97%, 98% or 99% sequence identity to SEQ ID NO:49, and a lightchain variable domain (VL) comprising a V Kappa sequence with at least75% sequence identity, or at least 80% sequence identity, or at least85% sequence identity, or at least 90% sequence identity, or at least95% sequence identity, or at least 97%, 98% or 99% sequence identity tothe amino acid sequence shown as SEQ ID NO:52 or the amino acid sequenceshown as SEQ ID NO:89.

This antibody, or antigen-binding region may comprise heavy chain CDRswhich are identical to CDR1, CDR2 and CDR3 of SEQ ID NO:49 and lightchain CDRs which are identical to CDR1, CDR2 and CDR3 of SEQ ID NO:89 orCDR1, CDR2 and CDR3 of SEQ ID NO:52, whilst exhibiting amino acidsequence variation within the framework regions.

In an exemplary embodiment this antibody or antigen binding fragmentthereof binds to an epitope within the peptide₅₂₃-RSEECLSGTWTQQICLPAIYKVFPNSAPLEGGTRLTICGWDFGFRRNNKFDLKKTRVLLGNESCTLTLSESTMNTLKCTVGPAMNKHFNMSIIISNGHGTTQYSTFSYVDP-₆₃₃ (SEQ ID NO: 136) in the PSI-IPT1 regionof human c-Met protein.

In an exemplary embodiment this antibody, or an antigen binding fragmentthereof, may be a strict antagonist of HGF-mediated activation of thehuman c-Met protein and may also inhibit HGF-independent activation ofthe human c-Met protein, and preferably does not induce significantdown-regulation of cell surface human c-Met protein.

In one embodiment this antibody may include the CH1 domain, hingeregion, CH2 domain and CH3 domain of a human antibody, in particularhuman IgG1, IgG2, IgG3 or IgG4.

In a further embodiment there is provided an isolated antibody, or anantigen binding fragment thereof, that specifically binds to a humanc-Met protein and is preferably a strict antagonist of HGF-mediatedactivation of the c-Met receptor, the antibody comprising a heavy chainvariable domain (VH) comprising the amino acid sequence shown as SEQ IDNO:49, or a humanised or affinity variant thereof, and a light chainvariable domain (VL) comprising the amino acid sequence shown as SEQ IDNO:52 or the amino acid sequence shown as SEQ ID NO:89 or a humanised,or affinity variant thereof.

In an exemplary embodiment this antibody or antigen binding fragmentthereof binds to an epitope within the peptide₅₂₃-RSEECLSGTWTQQICLPAIYKVFPNSAPLEGGTRLTICGWDFGFRRNNKFDLKKTRVLLGNESCTLTLSESTMNTLKCTVGPAMNKHFNMSIIISNGHGTTQYSTFSYVDP-₆₃₃ (SEQ ID NO: 136) in the PSI-IPT1 regionof human c-Met protein.

In an exemplary embodiment this antibody, or an antigen binding fragmentthereof, may be a strict antagonist of HGF-mediated activation of thehuman c-Met protein and may also inhibit HGF-independent activation ofthe human c-Met protein, and preferably does not induce significantdown-regulation of cell surface human c-Met protein.

In one embodiment this antibody may include the CH1 domain, hingeregion, CH2 domain and CH3 domain of a human antibody, in particularhuman IgG1, IgG2, IgG3 or IgG4.

In a further embodiment there is provided an isolated antibody, or anantigen binding fragment thereof which specifically binds human c-Metprotein, said antibody or antigen binding fragment comprising a heavychain variable domain (VH) comprising the amino acid sequence shown asSEQ ID NO:49, or a humanised or affinity variant thereof, and a lightchain variable domain (VL) comprising the amino acid sequence shown asSEQ ID NO:89 or a humanised, or affinity variant thereof.

In an exemplary embodiment this antibody or antigen binding fragmentthereof binds to an epitope within the peptide₅₂₃-RSEECLSGTWTQQICLPAIYKVFPNSAPLEGGTRLTICGWDFGFRRNNKFDLKKTRVLLGNESCTLTLSESTMNTLKCTVGPAMNKHFNMSIIISNGHGTTQYSTFSYVDP-₆₃₃ (SEQ ID NO: 136) in the PSI-IPT1 regionof human c-Met protein.

In an exemplary embodiment this antibody, or an antigen binding fragmentthereof, may be a strict antagonist of HGF-mediated activation of thehuman c-Met protein and may also inhibit HGF-independent activation ofthe human c-Met protein, and preferably does not induce significantdown-regulation of cell surface human c-Met protein.

In one embodiment this antibody may include the CH1 domain, hingeregion, CH2 domain and CH3 domain of a human antibody, in particularhuman IgG1, IgG2,

IgG3 or IgG4.

In a further embodiment there is provided an isolated antibody or anantigen binding fragment thereof that specifically binds to a humanc-Met protein and is preferably a strict antagonist of HGF-mediatedactivation of the c-Met receptor, which antibody is a human germlinedvariant of the antibody 48A2, said germlined variant antibodycomprising:—

(a) a heavy chain variable domain (VH) comprising the amino acidsequence shown as SEQ ID NO:108, and a light chain variable domain (VL)comprising the amino acid sequence shown as SEQ ID NO:109; or

(b) a heavy chain variable domain (VH) comprising the amino acidsequence shown as SEQ ID NO:110, and a light chain variable domain (VL)comprising the amino acid sequence shown as SEQ ID NO:111; or

(c) a heavy chain variable domain (VH) comprising the amino acidsequence shown as SEQ ID NO:112, and a light chain variable domain (VL)comprising the amino acid sequence shown as SEQ ID NO:113; or

(d) a heavy chain variable domain (VH) comprising the amino acidsequence shown as SEQ ID NO:114, and a light chain variable domain (VL)comprising the amino acid sequence shown as SEQ ID NO:115; or

(e) a heavy chain variable domain (VH) comprising the amino acidsequence shown as SEQ ID NO:116, and a light chain variable domain (VL)comprising the amino acid sequence shown as SEQ ID NO:117; or

(f) a heavy chain variable domain (VH) comprising the amino acidsequence shown as SEQ ID NO:118, and a light chain variable domain (VL)comprising the amino acid sequence shown as SEQ ID NO:119; or

(g) a heavy chain variable domain (VH) comprising the amino acidsequence shown as SEQ ID NO:120, and a light chain variable domain (VL)comprising the amino acid sequence shown as SEQ ID NO:121; or

(h) a heavy chain variable domain (VH) comprising the amino acidsequence shown as SEQ ID NO:49, and a light chain variable domain (VL)comprising an amino acid sequence selected from the group consisting ofSEQ ID NO:149, SEQ ID NO:150, SEQ ID NO:151, SEQ ID NO:152, SEQ IDNO:153, SEQ ID NO:154, SEQ ID NO:155, SEQ ID NO:156 and SEQ ID NO:157.

These variant 48A2 antibodies, or antigen-binding regions, areidentified as comprising a combination of a VH domain, defined byreference to a specific amino acid sequence, and a VL domain (V Kappa),also defined by reference to a specific amino acid sequence. For eachspecific VH/VL combination listed, this definition should be taken toinclude antibodies, or antigen binding regions, formed by combination ofa VH domain having at least 85%, at least 90%, at least 95%, at least97%, or at least 99% sequence identity to the stated VH amino acidsequence and a VL domain having at least 75%, at least 80%, at least85%, at least 90%, at least 95%, at least 97%, or at least 99% sequenceidentity to the stated VL amino acid sequence. In each case the VH andVL domains defined by % sequence identity to the stated VH and VL aminoacid sequences may retain identical CDR sequences to those present inthe stated VH and VL amino acid sequences, whilst exhibiting amino acidsequence variation within the framework regions.

In an exemplary embodiment this antibody or antigen binding fragmentthereof binds to an epitope within the peptide₅₂₃-RSEECLSGTWTQQICLPAIYKVFPNSAPLEGGTRLTICGWDFGFRRNNKFDLKKTRVLLGNESCTLTLSESTMNTLKCTVGPAMNKHFNMSIIISNGHGTTQYSTFSYVDP-₆₃₃ (SEQ ID NO: 136) in the PSI-IPT1 regionof human c-Met protein.

In an exemplary embodiment this antibody, or an antigen binding fragmentthereof, may be a strict antagonist of HGF-mediated activation of thehuman c-Met protein and may also inhibit HGF-independent activation ofthe human c-Met protein, and preferably does not induce significantdown-regulation of cell surface human c-Met protein.

In one embodiment this antibody may include the CH1 domain, hingeregion, CH2 domain and CH3 domain of a human antibody, in particularhuman IgG1, IgG2, IgG3 or IgG4.

In a further embodiment there is provided an isolated antibody or anantigen binding fragment thereof that specifically binds to a humanc-Met protein and is preferably a strict antagonist of HGF-mediatedactivation of the c-Met receptor, which antibody is an affinity variantof the reference antibody 48A2, said affinity variant antibodycomprising a heavy chain variable domain (VH) comprising the amino acidsequence shown as SEQ ID NO:49, and a light chain variable domain (VL)comprising an amino acid sequence selected from the group consisting ofSEQ ID NO:149, SEQ ID NO:150, SEQ ID NO:151, SEQ ID NO:152, SEQ IDNO:153, SEQ ID NO:154, SEQ ID NO:155, SEQ ID NO:156 and SEQ ID NO:157.

In an exemplary embodiment this antibody, or an antigen binding fragmentthereof, may be a strict antagonist of HGF-mediated activation of thehuman c-Met protein and may also inhibit HGF-independent activation ofthe human c-Met protein, and preferably does not induce significantdown-regulation of cell surface human c-Met protein.

In one embodiment this antibody may include the CH1 domain, hingeregion, CH2 domain and CH3 domain of a human antibody, in particularhuman IgG1, IgG2, IgG3 or IgG4.

In a further embodiment there is provided an isolated antibody, or anantigen binding fragment thereof, that specifically binds to a humanc-Met protein and is preferably a strict antagonist of HGF-mediatedactivation of the c-Met receptor, the antibody comprising a heavy chainvariable domain (VH) comprising the amino acid sequence shown as SEQ IDNO:50, or a humanised or affinity variant thereof, and a light chainvariable domain (VL) comprising the amino acid sequence shown as SEQ IDNO:53, or a humanised, or affinity variant thereof.

In an exemplary embodiment this antibody, or an antigen binding fragmentthereof, may be a strict antagonist of HGF-mediated activation of thehuman c-Met protein and may also inhibit HGF-independent activation ofthe human c-Met protein, and preferably does not induce significantdown-regulation of cell surface human c-Met protein.

In one embodiment this antibody may include the CH1 domain, hingeregion, CH2 domain and CH3 domain of a human antibody, in particularhuman IgG1, IgG2, IgG3 or IgG4.

20A11, 13E6, 12G4

In a further embodiment there is provided an isolated antibody, or anantigen binding fragment thereof which specifically binds human c-Metprotein, said antibody or antigen binding fragment comprising a heavychain variable domain wherein the variable heavy chain CDR3 sequence isselected from the group consisting of SEQ ID NO:3, SEQ ID NO:6 or SEQ IDNO:9 or sequence variant thereof, wherein the sequence variant comprisesone, two or three amino acid substitutions (e.g., conservativesubstitutions, humanising substitutions or affinity variants) in therecited sequence.

In one embodiment of the antibody or antigen binding fragment thereof

the variable heavy chain CDR3 sequence is selected from the groupconsisting of SEQ ID NO:3, SEQ ID NO:6 or SEQ ID NO:9 or sequencevariant thereof;

the variable heavy chain CDR2 sequence is SEQ ID NO:195 or sequencevariant thereof; and

the variable heavy chain CDR1 sequence is SEQ ID NO:198 or sequencevariant thereof, and

wherein the sequence variant comprises one, two or three amino acidsubstitutions (e.g., conservative substitutions, humanisingsubstitutions or affinity variants) in the recited sequence.

In one embodiment of the antibody or antigen binding fragment thereofthe variable heavy chain CDR3 sequence is SEQ ID NO:3 or sequencevariant thereof;

the variable heavy chain CDR2 sequence is SEQ ID NO:2 or sequencevariant thereof; and

the variable heavy chain CDR1 sequence is SEQ ID NO:1 or sequencevariant thereof, and

wherein the sequence variant comprises one, two or three amino acidsubstitutions (e.g., conservative substitutions, humanisingsubstitutions or affinity variants) in the recited sequence.

In one embodiment of the antibody or antigen binding fragment thereofthe variable heavy chain CDR3 sequence is SEQ ID NO:6 or sequencevariant thereof;

the variable heavy chain CDR2 sequence is SEQ ID NO:5 or sequencevariant thereof; and

the variable heavy chain CDR1 sequence is SEQ ID NO:4 or sequencevariant thereof, and

wherein the sequence variant comprises one, two or three amino acidsubstitutions (e.g., conservative substitutions, humanisingsubstitutions or affinity variants) in the recited sequence.

In one embodiment of the antibody or antigen binding fragment thereofthe variable heavy chain CDR3 sequence is SEQ ID NO:9 or sequencevariant thereof;

the variable heavy chain CDR2 sequence is SEQ ID NO:8 or sequencevariant thereof; and

the variable heavy chain CDR1 sequence is SEQ ID NO:7 or sequencevariant thereof, and

wherein the sequence variant comprises one, two or three amino acidsubstitutions (e.g., conservative substitutions, humanisingsubstitutions or affinity variants) in the recited sequence.

In one embodiment the antibody or antigen binding fragment thereoffurther comprises a light chain variable domain wherein the variablelight chain CDR3 sequence is SEQ ID NO:202 or sequence variant thereof;

the variable light chain CDR2 sequence is SEQ ID NO:204 or sequencevariant thereof; and

the variable light chain CDR1 sequence is SEQ ID NO:206 or sequencevariant thereof, and

wherein the sequence variant comprises one, two or three amino acidsubstitutions (e.g., conservative substitutions, humanisingsubstitutions or affinity variants) in the recited sequence.

In one embodiment of the antibody or antigen binding fragment thereofthe variable light chain CDR3 sequence is SEQ ID NO:36 or sequencevariant thereof;

the variable light chain CDR2 sequence is SEQ ID NO:35 or sequencevariant thereof; and

the variable light chain CDR1 sequence is SEQ ID NO:34 or sequencevariant thereof, and

wherein the sequence variant comprises one, two or three amino acidsubstitutions (e.g., conservative substitutions, humanisingsubstitutions or affinity variants) in the recited sequence.

In one embodiment of the antibody or antigen binding fragment thereofthe variable light chain CDR3 sequence is SEQ ID NO:39 or sequencevariant thereof;

the variable light chain CDR2 sequence is SEQ ID NO:38 or sequencevariant thereof; and

the variable light chain CDR1 sequence is SEQ ID NO:37 or sequencevariant thereof, and

wherein the sequence variant comprises one, two or three amino acidsubstitutions (e.g., conservative substitutions, humanisingsubstitutions or affinity variants) in the recited sequence.

In one embodiment of the antibody or antigen binding fragment thereofthe variable light chain CDR3 sequence is SEQ ID NO:42 or sequencevariant thereof;

the variable light chain CDR2 sequence is SEQ ID NO:41 or sequencevariant thereof; and

the variable light chain CDR1 sequence is SEQ ID NO:40 or sequencevariant thereof, and

wherein the sequence variant comprises one, two or three amino acidsubstitutions (e.g., conservative substitutions, humanisingsubstitutions or affinity variants) in the recited sequence.

In a further embodiment there is provided an isolated monoclonalantibody or antigen binding fragment thereof, wherein said antibody orantigen binding fragment specifically binds human c-Met protein, saidantibody or antigen binding fragment comprising a heavy chain variabledomain and a light chain variable domain, wherein:

the variable heavy chain CDR3 sequence is SEQ ID NO:9 or sequencevariant thereof;

the variable heavy chain CDR2 sequence is SEQ ID NO:8 or sequencevariant thereof; and

the variable heavy chain CDR1 sequence is SEQ ID NO:7 or sequencevariant thereof,

the variable light chain CDR3 sequence is SEQ ID NO:42 or sequencevariant thereof;

the variable light chain CDR2 sequence is SEQ ID NO:41 or sequencevariant thereof; and

the variable light chain CDR1 sequence is SEQ ID NO:40 or sequencevariant thereof, and

wherein the sequence variant comprises one, two or three amino acidsubstitutions (e.g., conservative substitutions, humanisingsubstitutions or affinity variants) in the recited sequence.

In an exemplary embodiment this antibody, or an antigen binding fragmentthereof, may be a strict antagonist of HGF-mediated activation of thehuman c-Met protein and may also inhibit HGF-independent activation ofthe human c-Met protein, and preferably does not induce significantdown-regulation of cell surface human c-Met protein.

In one embodiment this antibody may include the CH1 domain, hingeregion, CH2 domain and CH3 domain of a human antibody, in particularhuman IgG1, IgG2, IgG3 or IgG4.

In a further embodiment there is provided an isolated monoclonalantibody or antigen binding fragment thereof, wherein said antibody orantigen binding fragment specifically binds human c-Met protein, saidantibody or antigen binding fragment comprising a heavy chain variabledomain and a light chain variable domain, wherein:

the variable heavy chain CDR3 sequence is SEQ ID NO:6 or sequencevariant thereof;

the variable heavy chain CDR2 sequence is SEQ ID NO:5 or sequencevariant thereof; and

the variable heavy chain CDR1 sequence is SEQ ID NO:4 or sequencevariant thereof,

the variable light chain CDR3 sequence is SEQ ID NO:39 or sequencevariant thereof;

the variable light chain CDR2 sequence is SEQ ID NO:38 or sequencevariant thereof; and

the variable light chain CDR1 sequence is SEQ ID NO:37 or sequencevariant thereof, and

wherein the sequence variant comprises one, two or three amino acidsubstitutions (e.g., conservative substitutions, humanisingsubstitutions or affinity variants) in the recited sequence.

In an exemplary embodiment this antibody, or an antigen binding fragmentthereof, may be a strict antagonist of HGF-mediated activation of thehuman c-Met protein and may also inhibit HGF-independent activation ofthe human c-Met protein, and preferably does not induce significantdown-regulation of cell surface human c-Met protein.

In one embodiment this antibody may include the CH1 domain, hingeregion, CH2 domain and CH3 domain of a human antibody, in particularhuman IgG1, IgG2, IgG3 or IgG4.

In a further embodiment there is provided an isolated monoclonalantibody or antigen binding fragment thereof, wherein said antibody orantigen binding fragment specifically binds human c-Met protein, saidantibody or antigen binding fragment comprising a heavy chain variabledomain and a light chain variable domain, wherein:

the variable heavy chain CDR3 sequence is SEQ ID NO:3 or sequencevariant thereof;

the variable heavy chain CDR2 sequence is SEQ ID NO:2 or sequencevariant thereof; and

the variable heavy chain CDR1 sequence is SEQ ID NO:1 or sequencevariant thereof,

the variable light chain CDR3 sequence is SEQ ID NO:36 or sequencevariant thereof;

the variable light chain CDR2 sequence is SEQ ID NO:35 or sequencevariant thereof; and

the variable light chain CDR1 sequence is SEQ ID NO:34 or sequencevariant thereof, and

wherein the sequence variant comprises one, two or three amino acidsubstitutions (e.g., conservative substitutions, humanisingsubstitutions or affinity variants) in the recited sequence.

In an exemplary embodiment this antibody, or an antigen binding fragmentthereof, may be a strict antagonist of HGF-mediated activation of thehuman c-Met protein and may also inhibit HGF-independent activation ofthe human c-Met protein, and preferably does not induce significantdown-regulation of cell surface human c-Met protein.

In one embodiment this antibody may include the CH1 domain, hingeregion, CH2 domain and CH3 domain of a human antibody, in particularhuman IgG1, IgG2, IgG3 or IgG4.

In a further embodiment there is provided an isolated monoclonalantibody or antigen binding fragment thereof, wherein said antibody orantigen binding fragment specifically binds human c-Met protein, saidantibody or antigen binding fragment comprising a heavy chain variabledomain and a light chain variable domain, the heavy chain variabledomain comprising a VH sequence with at least 85% sequence identity, orat least 90% sequence identity, or at least 95% sequence identity, or atleast 97%, 98% or 99% sequence identity, to an amino acid sequenceselected from the group consisting of: SEQ ID NO:45, 46 and 47.

In a further embodiment there is provided an isolated monoclonalantibody or antigen binding fragment thereof, wherein said antibody orantigen binding fragment specifically binds human c-Met protein, saidantibody or antigen binding fragment comprising a heavy chain variabledomain and a light chain variable domain, the heavy chain variabledomain comprising a VH amino acid sequence selected from the groupconsisting of: SEQ ID NO:45, 46 and 47.

In a further embodiment there is provided an isolated monoclonalantibody or antigen binding fragment thereof, wherein said antibody orantigen binding fragment specifically binds human c-Met protein, saidantibody or antigen binding fragment comprising a heavy chain variabledomain and a light chain variable domain, the light chain variabledomain comprising a V Lambda sequence with at least 80% sequenceidentity, or at least 85% sequence identity, or at least 90% sequenceidentity, or at least 95% sequence identity, or at least 97%, 98% or 99%sequence identity, to an amino acid sequence selected from the groupconsisting of SEQ ID NO: 56, 57 and 58.

In a further embodiment there is provided an isolated antibody orantigen binding fragment thereof, wherein said antibody or antigenbinding fragment specifically binds human c-Met protein, said antibodyor antigen binding fragment comprising a heavy chain variable domain anda light chain variable domain, the light chain variable domaincomprising a V Lambda amino acid sequence selected from the groupconsisting of SEQ ID NO:56, 57 and 58.

In a further embodiment there is provided an isolated antibody, or anantigen binding fragment thereof, that specifically binds to a humanc-Met protein and is preferably a strict antagonist of HGF-mediatedactivation of the c-Met receptor, the antibody comprising a heavy chainvariable domain (VH) comprising the amino acid sequence shown as SEQ IDNO:45, or a humanised or affinity variant thereof, and a light chainvariable domain (VL) comprising the amino acid sequence shown as SEQ IDNO:56, or a humanised, or affinity variant thereof.

In an exemplary embodiment this antibody, or an antigen binding fragmentthereof, may be a strict antagonist of HGF-mediated activation of thehuman c-Met protein and may also inhibit HGF-independent activation ofthe human c-Met protein, and preferably does not induce significantdown-regulation of cell surface human c-Met protein.

In one embodiment this antibody may include the CH1 domain, hingeregion, CH2 domain and CH3 domain of a human antibody, in particularhuman IgG1, IgG2, IgG3 or IgG4.

In a further embodiment there is provided an isolated antibody, or anantigen binding fragment thereof, that specifically binds to a humanc-Met protein and is preferably a strict antagonist of HGF-mediatedactivation of the c-Met receptor, the antibody comprising a heavy chainvariable domain (VH) comprising the amino acid sequence shown as SEQ IDNO;46, or a humanised or affinity variant thereof, and a light chainvariable domain (VL) comprising the amino acid sequence shown as SEQ IDNO:57, or a humanised, or affinity variant thereof.

In an exemplary embodiment this antibody, or an antigen binding fragmentthereof, may be a strict antagonist of HGF-mediated activation of thehuman c-Met protein and may also inhibit HGF-independent activation ofthe human c-Met protein, and preferably does not induce significantdown-regulation of cell surface human c-Met protein.

In one embodiment this antibody may include the CH1 domain, hingeregion, CH2 domain and CH3 domain of a human antibody, in particularhuman IgG1, IgG2, IgG3 or IgG4.

In a further embodiment there is provided an isolated antibody, or anantigen binding fragment thereof, that specifically binds to a humanc-Met protein and is a strict antagonist of HGF-mediated activation ofthe c-Met receptor, the antibody comprising a heavy chain variabledomain (VH) comprising the amino acid sequence shown as SEQ ID NO:47, ora humanised or affinity variant thereof, and a light chain variabledomain (VL) comprising the amino acid sequence shown as SEQ ID NO:58, ora humanised, or affinity variant thereof.

In an exemplary embodiment this antibody, or an antigen binding fragmentthereof, may be a strict antagonist of HGF-mediated activation of thehuman c-Met protein and may also inhibit HGF-independent activation ofthe human c-Met protein, and preferably does not induce significantdown-regulation of cell surface human c-Met protein.

In one embodiment this antibody may include the CH1 domain, hingeregion, CH2 domain and CH3 domain of a human antibody, in particularhuman IgG1, IgG2, IgG3 or IgG4.

34H7

In a further embodiment there is provided an isolated antibody orantigen binding fragment thereof which specifically binds human c-Metprotein, said antibody or antigen binding fragment comprising a heavychain variable domain wherein the variable heavy chain CDR3 sequence isSEQ ID NO:73 or sequence variant thereof, wherein the sequence variantcomprises one, two or three amino acid substitutions (e.g., conservativesubstitutions, humanising substitutions or affinity variants) in therecited sequence.

In one embodiment of the antibody or antigen binding fragment

the variable heavy chain CDR3 sequence is SEQ ID NO:73 or sequencevariant thereof;

the variable heavy chain CDR2 sequence is SEQ ID NO:72 or sequencevariant thereof; and

the variable heavy chain CDR1 sequence is SEQ ID NO:71 or sequencevariant thereof, and

wherein the sequence variant comprises one, two or three amino acidsubstitutions (e.g., conservative substitutions, humanisingsubstitutions or affinity variants) in the recited sequence.

In one embodiment the antibody or antigen binding fragment furthercomprises a light chain variable domain wherein

the variable light chain CDR3 sequence is SEQ ID NO:76 or sequencevariant thereof;

the variable light chain CDR2 sequence is SEQ ID NO:75 or sequencevariant thereof; and

the variable light chain CDR1 sequence is SEQ ID NO:74 or sequencevariant thereof, and

wherein the sequence variant comprises one, two or three amino acidsubstitutions (e.g., conservative substitutions, humanisingsubstitutions or affinity variants) in the recited sequence.

In an exemplary embodiment this antibody, or an antigen binding fragmentthereof, comprising all six recited heavy chain and light chain CDRs,may be a strict antagonist of HGF-mediated activation of the human c-Metprotein and may also inhibit HGF-independent activation of the humanc-Met protein, and preferably does not induce significantdown-regulation of cell surface human c-Met protein.

In one embodiment this antibody may include the CH1 domain, hingeregion, CH2 domain and CH3 domain of a human antibody, in particularhuman IgG1, IgG2, IgG3 or IgG4.

In a further embodiment there is provided an isolated monoclonalantibody or antigen binding fragment thereof, wherein said antibody orantigen binding fragment specifically binds human c-Met protein, saidantibody or antigen binding fragment comprising a heavy chain variabledomain and a light chain variable domain, the heavy chain variabledomain comprising a VH sequence with at least 85% sequence identity, orat least 90% sequence identity, or at least 95% sequence identity, or atleast 97%, 98% or 99% sequence identity, to the amino acid sequenceshown as SEQ ID NO:77.

In a further embodiment there is provided an isolated monoclonalantibody or antigen binding fragment thereof, wherein said antibody orantigen binding fragment specifically binds human c-Met protein, saidantibody or antigen binding fragment comprising a heavy chain variabledomain and a light chain variable domain, the heavy chain variabledomain comprising the VH amino acid sequence shown as SEQ ID NO:77.

In a further embodiment there is provided an isolated monoclonalantibody or antigen binding fragment thereof, wherein said antibody orantigen binding fragment specifically binds human c-Met protein, saidantibody or antigen binding fragment comprising a heavy chain variabledomain and a light chain variable domain, the light chain variabledomain comprising a V Lambda sequence with at least 80% sequenceidentity, or at least 85% sequence identity, or at least 90% sequenceidentity, or at least 95% sequence identity, or at least 97%, 98% or 99%sequence identity, to the amino acid sequence shown as SEQ ID NO:78.

In a further embodiment there is provided an isolated antibody orantigen binding fragment thereof, wherein said antibody or antigenbinding fragment specifically binds human c-Met protein, said antibodyor antigen binding fragment comprising a heavy chain variable domain anda light chain variable domain, the light chain variable domaincomprising the VL amino acid sequence shown as SEQ ID NO:78.

In a further embodiment there is provided an isolated antibody, or anantigen binding fragment thereof, that specifically binds to a humanc-Met protein and is preferably a strict antagonist of HGF-mediatedactivation of the c-Met receptor, the antibody comprising a heavy chainvariable domain (VH) comprising the amino acid sequence shown as SEQ IDNO:77, or a humanised or affinity variant thereof, and a light chainvariable domain (VL) comprising the amino acid sequence shown as SEQ IDNO:78, or a humanised, or affinity variant thereof.

In an exemplary embodiment this antibody, or an antigen binding fragmentthereof, may be a strict antagonist of HGF-mediated activation of thehuman c-Met protein and may also inhibit HGF-independent activation ofthe human c-Met protein, and preferably does not induce significantdown-regulation of cell surface human c-Met protein.

In one embodiment this antibody may include the CH1 domain, hingeregion, CH2 domain and CH3 domain of a human antibody, in particularhuman IgG1, IgG2, IgG3 or IgG4.

Where particular antibodies, or antigen-binding regions, are identifiedas comprising a combination of a VH domain, defined by reference to aspecific amino acid sequence, and a VL domain (V Kappa), also defined byreference to a specific amino acid sequence, then for each specificVH/VL combination listed (unless otherwise stated) this definition maybe taken to include antibodies, or antigen binding regions, formed bycombination of a VH domain having at least 85%, at least 90%, at least95%, at least 97%, or at least 99% sequence identity to the stated VHamino acid sequence and a VL domain having at least 75%, at least 80%,at least 85%, at least 90%, at least 95%, at least 97%, or at least 99%sequence identity to the stated VL amino acid sequence. In each case theVH and VL domains defined by % sequence identity to the stated VH and VLamino acid sequences may retain identical CDR sequences to those presentin the stated VH and VL amino acid sequences, whilst exhibiting aminoacid sequence variation within the framework regions.

Unless otherwise stated in the present application, % sequence identitybetween two amino acid sequences may be determined by comparing thesetwo sequences aligned in an optimum manner and in which the amino acidsequence to be compared can comprise additions or deletions with respectto the reference sequence for an optimum alignment between these twosequences. The percentage of identity is calculated by determining thenumber of identical positions for which the amino acid residue isidentical between the two sequences, by dividing this number ofidentical positions by the total number of positions in the comparisonwindow and by multiplying the result obtained by 100 in order to obtainthe percentage of identity between these two sequences. For example, itis possible to use the BLAST program, “BLAST 2 sequences” (Tatusova etal, “Blast 2 sequences—a new tool for comparing protein and nucleotidesequences”, FEMS Microbiol Lett. 174:247-250) available on the sitehttp://www.ncbi.nlm.nih.gov/gorf/bl2.html, the parameters used beingthose given by default (in particular for the parameters “open gappenalty”: 5, and “extension gap penalty”: 2; the matrix chosen being,for example, the matrix “BLOSUM 62” proposed by the program), thepercentage of identity between the two sequences to be compared beingcalculated directly by the program.

The c-Met antibodies, or antigen binding fragments thereof, providedherein may each exhibit one or more, or any combination, of thefollowing properties/features:

The antibody or antigen binding fragment may act as an inhibitor ofHGF-independent activation of the c-Met receptor.

The antibody or antigen binding fragment may inhibit HGF-independentdimerisation, and more particularly homodimerization and/orheterodimerisation, of human c-Met protein.

The antibody may exhibit one or more effector functions selected fromantibody-dependent cell-mediated cytotoxicity (ADCC), complementdependent cytotoxicity (CDC) and antibody-dependent cell-mediatedphagocytosis (ADCP) against cells expressing human c-Met protein on thecell surface.

The antibody may exhibit ADCC against c-Met-addicted cancer cells.

The antibody may exhibit enhanced ADCC function in comparison to areference antibody which is an equivalent antibody comprising a nativehuman Fc domain. In a non-limiting embodiment, the ADCC function may beat least 10× enhanced in comparison to the reference antibody comprisinga native human Fc domain. In this context “equivalent” may be taken tomean that the antibody with enhanced ADCC function displayssubstantially identical antigen-binding specificity and/or sharesidentical amino acid sequence with the reference antibody, except forany modifications made (relative to native human Fc) for the purposes ofenhancing ADCC.

The antibody may contain the hinge region, CH2 domain and CH3 domain ofa human IgG, most preferably human IgG1.

The antibody may include modifications in the Fc region, as explainedelsewhere herein. In particular, the antibody may be a non-fucosylatedIgG.

In further aspects, the invention also provides polynucleotide moleculeswhich encode the above-listed c-Met antibodies and antigen bindingfragments thereof, in addition to expression vectors comprising thepolynucleotides, host cells containing the vectors and methods ofrecombinant expression/production of the c-Met antibodies.

In a still further aspect, the invention provides a pharmaceuticalcomposition comprising any one of the c-Met antibodies described aboveand a pharmaceutically acceptable carrier or excipient.

A still further aspect of the invention concerns methods of medicaltreatment using the above-listed c-Met antibodies, particularly in thetreatment of cancer, including both HGF-dependent cancers andHGF-independent cancers.

Definitions

“Antibody” or “Immunoglobulin”—As used herein, the term “immunoglobulin”includes a polypeptide having a combination of two heavy and two lightchains whether or not it possesses any relevant specificimmunoreactivity. “Antibodies” refers to such assemblies which havesignificant known specific immunoreactive activity to an antigen ofinterest (e.g. human c-Met). The term “c-Met antibodies” is used hereinto refer to antibodies which exhibit immunological specificity for humanc-Met protein. As explained elsewhere herein, “specificity” for humanc-Met does not exclude cross-reaction with species homologues of c-Met.Antibodies and immunoglobulins comprise light and heavy chains, with orwithout an interchain covalent linkage between them. Basicimmunoglobulin structures in vertebrate systems are relatively wellunderstood.

The generic term “immunoglobulin” comprises five distinct classes ofantibody that can be distinguished biochemically. All five classes ofantibodies are within the scope of the present invention, the followingdiscussion will generally be directed to the IgG class of immunoglobulinmolecules. With regard to IgG, immunoglobulins comprise two identicallight polypeptide chains of molecular weight approximately 23,000Daltons, and two identical heavy chains of molecular weight53,000-70,000. The four chains are joined by disulfide bonds in a “Y”configuration wherein the light chains bracket the heavy chains startingat the mouth of the “Y” and continuing through the variable region.

The light chains of an antibody are classified as either kappa or lambda(κ, λ). Each heavy chain class may be bound with either a kappa orlambda light chain. In general, the light and heavy chains arecovalently bonded to each other, and the “tail” portions of the twoheavy chains are bonded to each other by covalent disulfide linkages ornon-covalent linkages when the immunoglobulins are generated either byhybridomas, B cells or genetically engineered host cells. In the heavychain, the amino acid sequences run from an N-terminus at the forkedends of the Y configuration to the C-terminus at the bottom of eachchain. Those skilled in the art will appreciate that heavy chains areclassified as gamma, mu, alpha, delta, or epsilon, (γ, μ, α, δ, ε) withsome subclasses among them (e.g., γ1-γ4). It is the nature of this chainthat determines the “class” of the antibody as IgG, IgM, IgA IgG, orIgE, respectively. The immunoglobulin subclasses (isotypes) e.g., IgG1,IgG2, IgG3, IgG4, IgA1, etc. are well characterized and are known toconfer functional specialization. Modified versions of each of theseclasses and isotypes are readily discernable to the skilled artisan inview of the instant disclosure and, accordingly, are within the scope ofthe instant invention.

As indicated above, the variable region of an antibody allows theantibody to selectively recognize and specifically bind epitopes onantigens. That is, the VL domain and VH domain of an antibody combine toform the variable region that defines a three dimensional antigenbinding site. This quaternary antibody structure forms the antigenbinding site present at the end of each arm of the Y. More specifically,the antigen binding site is defined by three complementary determiningregions (CDRs) on each of the VH and VL chains.

“c-Met protein” or “c-Met receptor”—As used herein, the terms “c-Metprotein” or “c-Met receptor” or “c-Met” are used interchangeably andrefer to the receptor tyrosine kinase that, in its wild-type form, bindsHepatocyte Growth Factor (HGF). The terms “human c-Met protein” or“human c-Met receptor” or “human c-Met” are used interchangeably torefer to human c-Met, including the native human c-Met protein naturallyexpressed in the human host and/or on the surface of human cultured celllines, as well as recombinant forms and fragments thereof and alsonaturally occurring mutant forms, polymorphic variants and functionallyactive mutant forms. Specific examples of human c-Met include, e.g., thehuman polypeptide encoded by the nucleotide sequence provided in GenBankAcc No. NM_000245, or the human protein encoded by the polypeptidesequence provided in GenBank Acc. No. NP_000236, or the extracellulardomain of thereof. The single chain precursor c-Met protein ispost-translationally cleaved to produce the alpha and beta subunits,which are disulfide linked to form the mature receptor. The c-Metantibodies provided herein typically bind both to mature human c-Metprotein as expressed on the cell surface, e.g. as expressed on the humangastric cell line MKN-45 and to recombinant human c-Met protein (e.g.recombinant dimeric c-Met obtainable from R&D systems, 358-MT/CF).

“Binding Site”—As used herein, the term “binding site” comprises aregion of a polypeptide which is responsible for selectively binding toa target antigen of interest (e.g. human c-Met). Binding domains orbinding regions comprise at least one binding site. Exemplary bindingdomains include an antibody variable domain. The antibody molecules ofthe invention may comprise a single antigen binding site or multiple(e.g., two, three or four) antigen binding sites.

“Derived From”—As used herein the term “derived from” a designatedprotein (e.g. a c-Met antibody or antigen-binding fragment thereof)refers to the origin of the polypeptide. In one embodiment, thepolypeptide or amino acid sequence which is derived from a particularstarting polypeptide is a CDR sequence or sequence related thereto. Inone embodiment, the amino acid sequence which is derived from aparticular starting polypeptide is not contiguous. For example, in oneembodiment, one, two, three, four, five, or six CDRs are derived from astarting antibody. In one embodiment, the polypeptide or amino acidsequence which is derived from a particular starting polypeptide oramino acid sequence has an amino acid sequence that is essentiallyidentical to that of the starting sequence, or a portion thereof whereinthe portion consists of at least of at least 3-5 amino acids, 5-10 aminoacids, at least 10-20 amino acids, at least 20-30 amino acids, or atleast 30-50 amino acids, or which is otherwise identifiable to one ofordinary skill in the art as having its origin in the starting sequence.In one embodiment, the one or more CDR sequences derived from thestarting antibody are altered to produce variant CDR sequences, e.g.affinity variants, wherein the variant CDR sequences maintain c-Metbinding activity.

“Camelid-Derived”—In certain preferred embodiments, the cMet antibodymolecules of the invention comprise framework amino acid sequencesand/or CDR amino acid sequences derived from a camelid conventionalantibody raised by active immunisation of a camelid with c-Met antigen.However, c-Met antibodies comprising camelid-derived amino acidsequences may be engineered to comprise framework and/or constant regionsequences derived from a human amino acid sequence or other non-camelidmammalian species. For example, a human or non-human primate frameworkregion, heavy chain portion, and/or hinge portion may be included in thesubject c-Met antibodies. In one embodiment, one or more non-camelidamino acids may be present in the framework region of a“camelid-derived” c-Met antibody, e.g., a camelid framework amino acidsequence may comprise one or more amino acid mutations in which thecorresponding human or non-human primate amino acid residue is present.Moreover, camelid-derived VH and VL domains, or humanised variantsthereof, may be linked to the constant domains of human antibodies toproduce a chimeric molecule, as extensively described elsewhere herein.

“Conservative amino acid substitution”—A “conservative amino acidsubstitution” is one in which the amino acid residue is replaced with anamino acid residue having a similar side chain. Families of amino acidresidues having similar side chains have been defined in the art,including basic side chains (e.g., lysine, arginine, histidine), acidicside chains (e.g., aspartic acid, glutamic acid), uncharged polar sidechains (e.g., glycine, asparagine, glutamine, serine, threonine,tyrosine, cysteine), nonpolar side chains (e.g., alanine, valine,leucine, isoleucine, proline, phenylalanine, methionine, tryptophan),beta-branched side chains (e.g., threonine, valine, isoleucine) andaromatic side chains (e.g., tyrosine, phenylalanine, tryptophan,histidine). Thus, a nonessential amino acid residue in an immunoglobulinpolypeptide may be replaced with another amino acid residue from thesame side chain family. In another embodiment, a string of amino acidscan be replaced with a structurally similar string that differs in orderand/or composition of side chain family members.

“Heavy chain portion”—As used herein, the term “heavy chain portion”includes amino acid sequences derived from the constant domains of animmunoglobulin heavy chain. A polypeptide comprising a heavy chainportion comprises at least one of: a CH1 domain, a hinge (e.g., upper,middle, and/or lower hinge region) domain, a CH2 domain, a CH3 domain,or a variant or fragment thereof. In one embodiment, a binding moleculeof the invention may comprise the Fc portion of an immunoglobulin heavychain (e.g., a hinge portion, a CH2 domain, and a CH3 domain). Inanother embodiment, a binding molecule of the invention lacks at least aportion of a constant domain (e.g., all or part of a CH2 domain) Incertain embodiments, at least one, and preferably all, of the constantdomains are derived from a human immunoglobulin heavy chain. Forexample, in one preferred embodiment, the heavy chain portion comprisesa fully human hinge domain. In other preferred embodiments, the heavychain portion comprising a fully human Fc portion (e.g., hinge, CH2 andCH3 domain sequences from a human immunoglobulin). In certainembodiments, the constituent constant domains of the heavy chain portionare from different immunoglobulin molecules. For example, a heavy chainportion of a polypeptide may comprise a CH2 domain derived from an IgG1molecule and a hinge region derived from an IgG3 or IgG4 molecule. Inother embodiments, the constant domains are chimeric domains comprisingportions of different immunoglobulin molecules. For example, a hinge maycomprise a first portion from an IgG1 molecule and a second portion froman IgG3 or IgG4 molecule. As set forth above, it will be understood byone of ordinary skill in the art that the constant domains of the heavychain portion may be modified such that they vary in amino acid sequencefrom the naturally occurring (wild-type) immunoglobulin molecule. Thatis, the polypeptides of the invention disclosed herein may comprisealterations or modifications to one or more of the heavy chain constantdomains (CHL hinge, CH2 or CH3) and/or to the light chain constantdomain (CL). Exemplary modifications include additions, deletions orsubstitutions of one or more amino acids in one or more domains.

“Chimeric”—A “chimeric” protein comprises a first amino acid sequencelinked to a second amino acid sequence with which it is not naturallylinked in nature. The amino acid sequences may normally exist inseparate proteins that are brought together in the fusion polypeptide orthey may normally exist in the same protein but are placed in a newarrangement in the fusion polypeptide. A chimeric protein may becreated, for example, by chemical synthesis, or by creating andtranslating a polynucleotide in which the peptide regions are encoded inthe desired relationship. Exemplary chimeric c-Met antibodies includefusion proteins comprising camelid-derived VH and VL domains, orhumanised variants thereof, fused to the constant domains of a humanantibody, e.g. human IgG1, IgG2, IgG3 or IgG4.

“Variable region” or “variable domain”—The term “variable” refers to thefact that certain portions of the variable domains VH and VL differextensively in sequence among antibodies and are used in the binding andspecificity of each particular antibody for its target antigen. However,the variability is not evenly distributed throughout the variabledomains of antibodies. It is concentrated in three segments called“hypervariable loops” in each of the VL domain and the VH domain whichform part of the antigen binding site. The first, second and thirdhypervariable loops of the VLambda light chain domain are referred toherein as L1(λ), L2(λ) and L3(λ) and may be defined as comprisingresidues 24-33 (L1(λ), consisting of 9, 10 or 11 amino acid residues),49-53 (L2(λ), consisting of 3 residues) and 90-96 (L3(λ), consisting of5 residues) in the VL domain (Morea et al., Methods 20:267-279 (2000)).The first, second and third hypervariable loops of the VKappa lightchain domain are referred to herein as L1(κ), L2(κ) and L3(κ) and may bedefined as comprising residues 25-33 (L1(κ), consisting of 6, 7, 8, 11,12 or 13 residues), 49-53 (L2(κ), consisting of 3 residues) and 90-97(L3(κ), consisting of 6 residues) in the VL domain (Morea et al.,Methods 20:267-279 (2000)). The first, second and third hypervariableloops of the VH domain are referred to herein as H1, H2 and H3 and maybe defined as comprising residues 25-33 (H1, consisting of 7, 8 or 9residues), 52-56 (H2, consisting of 3 or 4 residues) and 91-105 (H3,highly variable in length) in the VH domain (Morea et al., Methods20:267-279 (2000)).

Unless otherwise indicated, the terms L1, L2 and L3 respectively referto the first, second and third hypervariable loops of a VL domain, andencompass hypervariable loops obtained from both Vkappa and Vlambdaisotypes. The terms H1, H2 and H3 respectively refer to the first,second and third hypervariable loops of the VH domain, and encompasshypervariable loops obtained from any of the known heavy chain isotypes,including γ, ε, δ, α or μ.

The hypervariable loops L1, L2, L3, H1, H2 and H3 may each comprise partof a “complementarity determining region” or “CDR”, as defined below.The terms “hypervariable loop” and “complementarity determining region”are not strictly synonymous, since the hypervariable loops (HVs) aredefined on the basis of structure, whereas complementarity determiningregions (CDRs) are defined based on sequence variability (Kabat et al.,Sequences of Proteins of Immunological Interest, 5th Ed. Public HealthService, National Institutes of Health, Bethesda, Md., 1983) and thelimits of the HVs and the CDRs may be different in some VH and VLdomains

The CDRs of the VL and VH domains can typically be defined as comprisingthe following amino acids: residues 24-34 (CDRL1), 50-56 (CDRL2) and89-97 (CDRL3) in the light chain variable domain, and residues 31-35 or31-35b (CDRH1), 50-65 (CDRH2) and 95-102 (CDRH3) in the heavy chainvariable domain; (Kabat et al., Sequences of Proteins of ImmunologicalInterest, 5th Ed. Public Health Service, National Institutes of Health,Bethesda, Md. (1991)). Thus, the HVs may be comprised within thecorresponding CDRs and references herein to the “hypervariable loops” ofVH and VL domains should be interpreted as also encompassing thecorresponding CDRs, and vice versa, unless otherwise indicated.

The more highly conserved portions of variable domains are called theframework region (FR), as defined below. The variable domains of nativeheavy and light chains each comprise four FRs (FR1, FR2, FR3 and FR4,respectively), largely adopting a (3-sheet configuration, connected bythe three hypervariable loops. The hypervariable loops in each chain areheld together in close proximity by the FRs and, with the hypervariableloops from the other chain, contribute to the formation of theantigen-binding site of antibodies. Structural analysis of antibodiesrevealed the relationship between the sequence and the shape of thebinding site formed by the complementarity determining regions (Chothiaet al., J. Mol. Biol. 227: 799-817 (1992)); Tramontano et al., J. Mol.Biol, 215:175-182 (1990)). Despite their high sequence variability, fiveof the six loops adopt just a small repertoire of main-chainconformations, called “canonical structures”. These conformations arefirst of all determined by the length of the loops and secondly by thepresence of key residues at certain positions in the loops and in theframework regions that determine the conformation through their packing,hydrogen bonding or the ability to assume unusual main-chainconformations.

“CDR”—As used herein, the term “CDR” or “complementarity determiningregion” means the non-contiguous antigen combining sites found withinthe variable region of both heavy and light chain polypeptides. Theseparticular regions have been described by Kabat et al., J. Biol. Chem.252, 6609-6616 (1977) and Kabat et al., Sequences of protein ofimmunological interest. (1991), and by Chothia et al., J. Mol. Biol.196:901-917 (1987) and by MacCallum et al., J. Mol. Biol. 262:732-745(1996) where the definitions include overlapping or subsets of aminoacid residues when compared against each other. The amino acid residueswhich encompass the CDRs as defined by each of the above citedreferences are set forth for comparison. Preferably, the term “CDR” is aCDR as defined by Kabat based on sequence comparisons.

TABLE 1 CDR definitions CDR Definitions Kabat¹ Chothia² MacCallum³ V_(H)CDR1 31-35 26-32 30-35 V_(H) CDR2 50-65 53-55 47-58 V_(H) CDR3  95-102 96-101  93-101 V_(L) CDR1 24-34 26-32 30-36 V_(L) CDR2 50-56 50-5246-55 V_(L) CDR3 89-97 91-96 89-96 ¹Residue numbering follows thenomenclature of Kabat et al., supra ²Residue numbering follows thenomenclature of Chothia et al., supra ³Residue numbering follows thenomenclature of MacCallum et al., supra

“Framework region”—The term “framework region” or “FR region” as usedherein, includes the amino acid residues that are part of the variableregion, but are not part of the CDRs (e.g., using the Kabat definitionof CDRs). Therefore, a variable region framework is between about100-120 amino acids in length but includes only those amino acidsoutside of the CDRs. For the specific example of a heavy chain variableregion and for the CDRs as defined by Kabat et al., framework region 1corresponds to the domain of the variable region encompassing aminoacids 1-30; framework region 2 corresponds to the domain of the variableregion encompassing amino acids 36-49; framework region 3 corresponds tothe domain of the variable region encompassing amino acids 66-94, andframework region 4 corresponds to the domain of the variable region fromamino acids 103 to the end of the variable region. The framework regionsfor the light chain are similarly separated by each of the light claimvariable region CDRs. Similarly, using the definition of CDRs by Chothiaet al. or McCallum et al. the framework region boundaries are separatedby the respective CDR termini as described above. In preferredembodiments the CDRs are as defined by Kabat.

In naturally occurring antibodies, the six CDRs present on eachmonomeric antibody are short, non-contiguous sequences of amino acidsthat are specifically positioned to form the antigen binding site as theantibody assumes its three dimensional configuration in an aqueousenvironment. The remainder of the heavy and light variable domains showless inter-molecular variability in amino acid sequence and are termedthe framework regions. The framework regions largely adopt a β-sheetconformation and the CDRs form loops which connect, and in some casesform part of, the β-sheet structure. Thus, these framework regions actto form a scaffold that provides for positioning the six CDRs in correctorientation by inter-chain, non-covalent interactions. The antigenbinding site formed by the positioned CDRs defines a surfacecomplementary to the epitope on the immunoreactive antigen. Thiscomplementary surface promotes the non-covalent binding of the antibodyto the immunoreactive antigen epitope. The position of CDRs can bereadily identified by one of ordinary skill in the art.

“Hinge region”—As used herein, the term “hinge region” includes theportion of a heavy chain molecule that joins the CH1 domain to the CH2domain. This hinge region comprises approximately 25 residues and isflexible, thus allowing the two N-terminal antigen binding regions tomove independently. Hinge regions can be subdivided into three distinctdomains: upper, middle, and lower hinge domains (Roux et al. J. Immunol.1998 161:4083). C-Met antibodies comprising a “fully human” hinge regionmay contain one of the hinge region sequences shown in Table 2 below.

TABLE 2 human hinge sequences IgG Upper hinge Middle hinge Lower hingeIgG1 EPKSCDKTHT CPPCP APELLGGP SEQ ID NO: 182 SEQ ID NO: 183SEQ ID NO: 184 IgG3 ELKTPLGDTTHT CPRCP (EPKSCDTPPPCPRCP)₃ APELLGGPSEQ ID NO: 185 SEQ ID NO: 186 SEQ ID NO: 187 SEQ ID NO: 184 IgG4 ESKYGPPCPSCP APEFLGGP SEQ ID NO: 188 SEQ ID NO: 189 SEQ ID NO: 190 IgG42 ERKCCVECPPPCP APPVAGP SEQ ID NO: 191 SEQ ID NO: 192 SEQ ID NO: 193

“CH2 domain”—As used herein the term “CH2 domain” includes the portionof a heavy chain molecule that extends, e.g., from about residue 244 toresidue 360 of an antibody using conventional numbering schemes(residues 244 to 360, Kabat numbering system; and residues 231-340, EUnumbering system, Kabat E A et al. Sequences of Proteins ofImmunological Interest. Bethesda, US Department of Health and HumanServices, NIH. 1991). The CH2 domain is unique in that it is not closelypaired with another domain. Rather, two N-linked branched carbohydratechains are interposed between the two CH2 domains of an intact nativeIgG molecule. It is also well documented that the CH3 domain extendsfrom the CH2 domain to the C-terminal of the IgG molecule and comprisesapproximately 108 residues.

“Fragment”—The term “fragment” refers to a part or portion of anantibody or antibody chain comprising fewer amino acid residues than anintact or complete antibody or antibody chain. The term “antigen-bindingfragment” refers to a polypeptide fragment of an immunoglobulin orantibody that binds antigen or competes with intact antibody (i.e., withthe intact antibody from which they were derived) for antigen binding(i.e., specific binding to human c-Met). As used herein, the term“fragment” of an antibody molecule includes antigen-binding fragments ofantibodies, for example, an antibody light chain variable domain (VL),an antibody heavy chain variable domain (VH), a single chain antibody(scFv), a F(ab′)2 fragment, a Fab fragment, an Fd fragment, an Fvfragment, a single domain antibody fragment (DAb), a one-armed(monovalent) antibody, or any antigen-binding molecule formed bycombination, assembly or conjugation of such antigen binding fragments.Fragments can be obtained, e.g., via chemical or enzymatic treatment ofan intact or complete antibody or antibody chain or by recombinantmeans.

“Valency”—As used herein the term “valency” refers to the number ofpotential target binding sites in a polypeptide. Each target bindingsite specifically binds one target molecule or specific site on a targetmolecule. When a polypeptide comprises more than one target bindingsite, each target binding site may specifically bind the same ordifferent molecules (e.g., may bind to different ligands or differentantigens, or different epitopes on the same antigen). The subjectbinding molecules preferably have at least one binding site specific fora human c-Met molecule. In particular embodiments the c-Met antibodiesprovided herein may be at least bivalent.

“Specificity”—The term “specificity” refers to the ability tospecifically bind (e.g., immunoreact with) a given target, e.g., c-Met.A polypeptide may be monospecific and contain one or more binding siteswhich specifically bind a target or a polypeptide may be multispecificand contain two or more binding sites which specifically bind the sameor different targets. In one embodiment, an antibody of the invention isspecific for more than one target. For example, in one embodiment, amultispecific binding molecule of the invention binds to c-Met and asecond molecule expressed on a tumor cell. Exemplary antibodies whichcomprise antigen binding sites that bind to antigens expressed on tumorcells are known in the art and one or more CDRs from such antibodies canbe included in an antibody of the invention.

“Synthetic”—As used herein the term “synthetic” with respect topolypeptides includes polypeptides which comprise an amino acid sequencethat is not naturally occurring. For example, non-naturally occurringpolypeptides which are modified forms of naturally occurringpolypeptides (e.g., comprising a mutation such as an addition,substitution or deletion) or which comprise a first amino acid sequence(which may or may not be naturally occurring) that is linked in a linearsequence of amino acids to a second amino acid sequence (which may ormay not be naturally occurring) to which it is not naturally linked innature.

“Engineered”—As used herein the term “engineered” includes manipulationof nucleic acid or polypeptide molecules by synthetic means (e.g. byrecombinant techniques, in vitro peptide synthesis, by enzymatic orchemical coupling of peptides or some combination of these techniques).Preferably, the antobodies of the invention are engineered, includingfor example, humanized and/or chimeric antibodies, and antibodies whichhave been engineered to improve one or more properties, such as antigenbinding, stability/half-life or effector function.

“Modified antibody”—As used herein, the term “modified antibody”includes synthetic forms of antibodies which are altered such that theyare not naturally occurring, e.g., antibodies that comprise at least twoheavy chain portions but not two complete heavy chains (such as, domaindeleted antibodies or minibodies); multispecific forms of antibodies(e.g., bispecific, trispecific, etc.) altered to bind to two or moredifferent antigens or to different epitopes on a single antigen); heavychain molecules joined to scFv molecules and the like. ScFv moleculesare known in the art and are described, e.g., in U.S. Pat. No.5,892,019. In addition, the term “modified antibody” includesmultivalent forms of antibodies (e.g., trivalent, tetravalent, etc.,antibodies that bind to three or more copies of the same antigen). Inanother embodiment, a modified antibody of the invention is a fusionprotein comprising at least one heavy chain portion lacking a CH2 domainand comprising a binding domain of a polypeptide comprising the bindingportion of one member of a receptor ligand pair.

The term “modified antibody” may also be used herein to refer to aminoacid sequence variants of a c-Met antibody. It will be understood by oneof ordinary skill in the art that a c-Met antibody may be modified toproduce a variant c-Met antibody which varies in amino acid sequence incomparison to the c-Met antibody from which it was derived. For example,nucleotide or amino acid substitutions leading to conservativesubstitutions or changes at “non-essential” amino acid residues may bemade (e.g., in CDR and/or framework residues) Amino acid substitutionscan include replacement of one or more amino acids with a naturallyoccurring or non-natural amino acid.

“Humanising substitutions”—As used herein, the term “humanisingsubstitutions” refers to amino acid substitutions in which the aminoacid residue present at a particular position in the VH or VL domainantibody c-Met antibody (for example a camelid-derived c-Met antibody)is replaced with an amino acid residue which occurs at an equivalentposition in a reference human VH or VL domain. The reference human VH orVL domain may be a VH or VL domain encoded by the human germline, inwhich case the substituted residues may be referred to as “germliningsubstitutions”. Humanising/germlining substitutions may be made in theframework regions and/or the CDRs of a c-Met antibody, defined herein.

“Affinity variants”—As used herein, the term “affinity variant” refersto “a variant antibody which exhibits one or more changes in amino acidsequence compared to a reference c-Met antibody, wherein the affinityvariant exhibits an altered affinity for the human c-Met protein incomparison to the reference antibody. Typically, affinity variants willexhibit an improved affinity for human c-Met, as compared to thereference c-Met antibody. The improvement may be either a lower K_(D),for human c-Met, or a faster off-rate for human c-Met or an alterationin the pattern of cross-reactivity with non-human c-Met homologues.Affinity variants typically exhibit one or more changes in amino acidsequence in the CDRs, as compared to the reference c-Met antibody. Suchsubstitutions may result in replacement of the original amino acidpresent at a given position in the CDRs with a different amino acidresidue, which may be a naturally occurring amino acid residue or anon-naturally occurring amino acid residue. The amino acid substitutionsmay be conservative or non-conservative.

“High human homology”—An antibody comprising a heavy chain variabledomain (VH) and a light chain variable domain (VL) will be considered ashaving high human homology if the VH domains and the VL domains, takentogether, exhibit at least 90% amino acid sequence identity to theclosest matching human germline VH and VL sequences. Antibodies havinghigh human homology may include antibodies comprising VH and VL domainsof native non-human antibodies which exhibit sufficiently high %sequence identity human germline sequences, including for exampleantibodies comprising VH and VL domains of camelid conventionalantibodies, as well as engineered, especially humanised, variants ofsuch antibodies and also “fully human” antibodies.

In one embodiment the VH domain of the antibody with high human homologymay exhibit an amino acid sequence identity or sequence homology of 80%or greater with one or more human VH domains across the frameworkregions FR1, FR2, FR3 and FR4. In other embodiments the amino acidsequence identity or sequence homology between the VH domain of thepolypeptide of the invention and the closest matching human germline VHdomain sequence may be 85% or greater, 90% or greater, 95% or greater,97% or greater, or up to 99% or even 100%.

In one embodiment the VH domain of the antibody with high human homologymay contain one or more (e.g. 1 to 10) amino acid sequence mis-matchesacross the framework regions FR1, FR2, FR3 and FR4, in comparison to theclosest matched human VH sequence.

In another embodiment the VL domain of the antibody with high humanhomology may exhibit a sequence identity or sequence homology of 80% orgreater with one or more human VL domains across the framework regionsFR1, FR2, FR3 and FR4. In other embodiments the amino acid sequenceidentity or sequence homology between the VL domain of the polypeptideof the invention and the closest matching human germline VL domainsequence may be 85% or greater 90% or greater, 95% or greater, 97% orgreater, or up to 99% or even 100%.

In one embodiment the VL domain of the antibody with high human homologymay contain one or more (e.g. 1 to 10) amino acid sequence mis-matchesacross the framework regions FR1, FR2, FR3 and FR4, in comparison to theclosest matched human VL sequence.

Before analyzing the percentage sequence identity between the antibodywith high human homology and human germline VH and VL, the canonicalfolds may be determined, which allows the identification of the familyof human germline segments with the identical combination of canonicalfolds for H1 and H2 or L1 and L2 (and L3). Subsequently the humangermline family member that has the highest degree of sequence homologywith the variable region of the antibody of interest is chosen forscoring the sequence homology. The determination of Chothia canonicalclasses of hypervariable loops L1, L2, L3, H1 and H2 can be performedwith the bioinformatics tools publicly available on webpagewww.bioinf.org.uk/abs/chothia.html.page. The output of the program showsthe key residue requirements in a datafile. In these datafiles, the keyresidue positions are shown with the allowed amino acids at eachposition. The sequence of the variable region of the antibody ofinterest is given as input and is first aligned with a consensusantibody sequence to assign the Kabat numbering scheme. The analysis ofthe canonical folds uses a set of key residue templates derived by anautomated method developed by Martin and Thornton (Martin et al., J.Mol. Biol. 263:800-815 (1996)).

With the particular human germline V segment known, which uses the samecombination of canonical folds for H1 and H2 or L1 and L2 (and L3), thebest matching family member in terms of sequence homology can bedetermined. With bioinformatics tools the percentage sequence identitybetween the VH and VL domain framework amino acid sequences of theantibody of interest and corresponding sequences encoded by the humangermline can be determined, but actually manual alignment of thesequences can be applied as well. Human immunoglobulin sequences can beidentified from several protein data bases, such as VBase(http://vbase.mrc-cpe.cam.ac.uk/) or the Pluckthun/Honegger database(http://www.bioc.unizh.ch/antibody/Sequences/Germlines. To compare thehuman sequences to the V regions of VH or VL domains in an antibody ofinterest a sequence alignment algorithm such as available via websiteslike www.expasy.ch/tools/#align can be used, but also manual alignmentwith the limited set of sequences can be performed. Human germline lightand heavy chain sequences of the families with the same combinations ofcanonical folds and with the highest degree of homology with theframework regions 1, 2, and 3 of each chain are selected and comparedwith the variable region of interest; also the FR4 is checked againstthe human germline JH and JK or JL regions.

Note that in the calculation of overall percent sequence homology theresidues of FR1, FR2 and FR3 are evaluated using the closest matchsequence from the human germline family with the identical combinationof canonical folds. Only residues different from the closest match orother members of the same family with the same combination of canonicalfolds are scored (NB—excluding any primer-encoded differences). However,for the purposes of humanization, residues in framework regionsidentical to members of other human germline families, which do not havethe same combination of canonical folds, can be considered “human”,despite the fact that these are scored “negative” according to thestringent conditions described above. This assumption is based on the“mix and match” approach for humanization, in which each of FR1, FR2,FR3 and FR4 is separately compared to its closest matching humangermline sequence and the humanized molecule therefore contains acombination of different FRs as was done by Qu and colleagues (Qu etla., Clin. Cancer Res. 5:3095-3100 (1999)) and Ono and colleagues (Onoet al., Mol. Immunol. 36:387-395 (1999)). The boundaries of theindividual framework regions may be assigned using the IMGT numberingscheme, which is an adaptation of the numbering scheme of Chothia(Lefranc et al., NAR 27: 209-212 (1999); http://imgt.cines.fr)

Antibodies with high human homology may comprise hypervariable loops orCDRs having human or human-like canonical folds, as discussed in detailbelow. In one embodiment at least one hypervariable loop or CDR ineither the VH domain or the VL domain of the antibody with high humanhomology may be obtained or derived from a VH or VL domain of anon-human antibody, for example a conventional antibody from a speciesof Camelidae, yet exhibit a predicted or actual canonical fold structurewhich is substantially identical to a canonical fold structure whichoccurs in human antibodies.

It is well established in the art that although the primary amino acidsequences of hypervariable loops present in both VH domains and VLdomains encoded by the human germline are, by definition, highlyvariable, all hypervariable loops, except CDR H3 of the VH domain, adoptonly a few distinct structural conformations, termed canonical folds(Chothia et al., J. Mol. Biol. 196:901-917 (1987); Tramontano et al.Proteins 6:382-94 (1989)), which depend on both the length of thehypervariable loop and presence of the so-called canonical amino acidresidues (Chothia et al., J. Mol. Biol. 196:901-917 (1987)). Actualcanonical structures of the hypervariable loops in intact VH or VLdomains can be determined by structural analysis (e.g. X-raycrystallography), but it is also possible to predict canonical structureon the basis of key amino acid residues which are characteristic of aparticular structure (discussed further below). In essence, the specificpattern of residues that determines each canonical structure forms a“signature” which enables the canonical structure to be recognised inhypervariable loops of a VH or VL domain of unknown structure; canonicalstructures can therefore be predicted on the basis of primary amino acidsequence alone.

The predicted canonical fold structures for the hypervariable loops ofany given VH or VL sequence in an antibody with high human homology canbe analysed using algorithms which are publicly available fromwww.bioinf.org.uk/abs/chothia.html,www.biochem.ucl.ac.uk/˜martin/antibodies.html andwww.bioc.unizh.ch/antibody/Sequences/Germlines/Vbase_hVk.html. Thesetools permit query VH or VL sequences to be aligned against human VH orVL domain sequences of known canonical structure, and a prediction ofcanonical structure made for the hypervariable loops of the querysequence.

In the case of the VH domain, H1 and H2 loops may be scored as having acanonical fold structure “substantially identical” to a canonical foldstructure known to occur in human antibodies if at least the first, andpreferable both, of the following criteria are fulfilled:

1. An identical length, determined by the number of residues, to theclosest matching human canonical structural class.

2. At least 33% identity, preferably at least 50% identity with the keyamino acid residues described for the corresponding human H1 and H2canonical structural classes.

(note for the purposes of the foregoing analysis the H1 and H2 loops aretreated separately and each compared against its closest matching humancanonical structural class)

The foregoing analysis relies on prediction of the canonical structureof the H1 and H2 loops of the antibody of interest. If the actualstructures of the H1 and H2 loops in the antibody of interest are known,for example based on X-ray crystallography, then the H1 and H2 loops inthe antibody of interest may also be scored as having a canonical foldstructure “substantially identical” to a canonical fold structure knownto occur in human antibodies if the length of the loop differs from thatof the closest matching human canonical structural class (typically by±1 or +2 amino acids) but the actual structure of the H1 and H2 loops inthe antibody of interest matches the structure of a human canonicalfold.

Key amino acid residues found in the human canonical structural classesfor the first and second hypervariable loops of human VH domains (H1 andH2) are described by Chothia et al., J. Mol. Biol. 227:799-817 (1992),the contents of which are incorporated herein in their entirety byreference. In particular, Table 3 on page 802 of Chothia et al., whichis specifically incorporated herein by reference, lists preferred aminoacid residues at key sites for H1 canonical structures found in thehuman germline, whereas Table 4 on page 803, also specificallyincorporated by reference, lists preferred amino acid residues at keysites for CDR H2 canonical structures found in the human germline.

In one embodiment, both H1 and H2 in the VH domain of the antibody withhigh human homology exhibit a predicted or actual canonical foldstructure which is substantially identical to a canonical fold structurewhich occurs in human antibodies.

Antibodies with high human homology may comprise a VH domain in whichthe hypervariable loops H1 and H2 form a combination of canonical foldstructures which is identical to a combination of canonical structuresknown to occur in at least one human germline VH domain. It has beenobserved that only certain combinations of canonical fold structures atH1 and H2 actually occur in VH domains encoded by the human germline. Inan embodiment H1 and H2 in the VH domain of the antibody with high humanhomology may be obtained from a VH domain of a non-human species, e.g. aCamelidae species, yet form a combination of predicted or actualcanonical fold structures which is identical to a combination ofcanonical fold structures known to occur in a human germline orsomatically mutated VH domain. In non-limiting embodiments H1 and H2 inthe VH domain of the antibody with high human homology may be obtainedfrom a VH domain of a non-human species, e.g. a Camelidae species, andform one of the following canonical fold combinations: 1-1, 1-2, 1-3,1-6, 1-4, 2-1, 3-1 and 3-5.

An antibody with high human homology may contain a VH domain whichexhibits both high sequence identity/sequence homology with human VH,and which contains hypervariable loops exhibiting structural homologywith human VH.

It may be advantageous for the canonical folds present at H1 and H2 inthe VH domain of the antibody with high human homology, and thecombination thereof, to be “correct” for the human VH germline sequencewhich represents the closest match with the VH domain of the antibodywith high human homology in terms of overall primary amino acid sequenceidentity. By way of example, if the closest sequence match is with ahuman germline VH3 domain, then it may be advantageous for H1 and H2 toform a combination of canonical folds which also occurs naturally in ahuman VH3 domain. This may be particularly important in the case ofantibodies with high human homology which are derived from non-humanspecies, e.g. antibodies containing VH and VL domains which are derivedfrom camelid conventional antibodies, especially antibodies containinghumanised camelid VH and VL domains

Thus, in one embodiment the VH domain of the c-Met antibody with highhuman homology may exhibit a sequence identity or sequence homology of80% or greater, 85% or greater, 90% or greater, 95% or greater, 97% orgreater, or up to 99% or even 100% with a human VH domain across theframework regions FR1, FR2, FR3 and FR4, and in addition H1 and H2 inthe same antibody are obtained from a non-human VH domain (e.g. derivedfrom a Camelidae species), but form a combination of predicted or actualcanonical fold structures which is the same as a canonical foldcombination known to occur naturally in the same human VH domain.

In other embodiments, L1 and L2 in the VL domain of the antibody withhigh human homology are each obtained from a VL domain of a non-humanspecies (e.g. a camelid-derived VL domain), and each exhibits apredicted or actual canonical fold structure which is substantiallyidentical to a canonical fold structure which occurs in humanantibodies.

As with the VH domains, the hypervariable loops of VL domains of bothVLambda and VKappa types can adopt a limited number of conformations orcanonical structures, determined in part by length and also by thepresence of key amino acid residues at certain canonical positions.

Within an antibody of interest having high human homology, L1, L2 and L3loops obtained from a VL domain of a non-human species, e.g. a Camelidaespecies, may be scored as having a canonical fold structure“substantially identical” to a canonical fold structure known to occurin human antibodies if at least the first, and preferable both, of thefollowing criteria are fulfilled:

1. An identical length, determined by the number of residues, to theclosest matching human structural class.

2. At least 33% identity, preferably at least 50% identity with the keyamino acid residues described for the corresponding human L1 or L2canonical structural classes, from either the VLambda or the VKapparepertoire.

(note for the purposes of the foregoing analysis the L1 and L2 loops aretreated separately and each compared against its closest matching humancanonical structural class)

The foregoing analysis relies on prediction of the canonical structureof the L1, L2 and L3 loops in the VL domain of the antibody of interest.If the actual structure of the L1, L2 and L3 loops is known, for examplebased on X-ray crystallography, then L1, L2 or L3 loops derived from theantibody of interest may also be scored as having a canonical foldstructure “substantially identical” to a canonical fold structure knownto occur in human antibodies if the length of the loop differs from thatof the closest matching human canonical structural class (typically by±1 or +2 amino acids) but the actual structure of the Camelidae loopsmatches a human canonical fold.

Key amino acid residues found in the human canonical structural classesfor the CDRs of human VLambda and VKappa domains are described by Moreaet al. Methods, 20: 267-279 (2000) and Martin et al., J. Mol. Biol.,263:800-815 (1996). The structural repertoire of the human VKappa domainis also described by Tomlinson et al. EMBO J. 14:4628-4638 (1995), andthat of the VLambda domain by Williams et al. J. Mol. Biol., 264:220-232(1996). The contents of all these documents are to be incorporatedherein by reference.

L1 and L2 in the VL domain of an antibody with high human homology mayform a combination of predicted or actual canonical fold structureswhich is identical to a combination of canonical fold structures knownto occur in a human germline VL domain. In non-limiting embodiments L1and L2 in the VLambda domain of an antibody with high human homology(e.g. an antibody containing a camelid-derived VL domain or a humanisedvariant thereof) may form one of the following canonical foldcombinations: 11-7, 13-7(A,B,C), 14-7(A,B), 12-11, 14-11 and 12-12 (asdefined in Williams et al. J. Mol. Biol. 264:220-32 (1996) and as shownon http://www.bioc.uzh.ch/antibody/Sequences/Germlines/VBase_hVL.html).In non-limiting embodiments L1 and L2 in the Vkappa domain may form oneof the following canonical fold combinations: 2-1, 3-1, 4-1 and 6-1 (asdefined in Tomlinson et al. EMBO J. 14:4628-38 (1995) and as shown onhttp://www.bioc.uzh.ch/antibody/Sequences/Germlines/VBase_hVK.html).

In a further embodiment, all three of L1, L2 and L3 in the VL domain ofan antibody with high human homology may exhibit a substantially humanstructure. It is preferred that the VL domain of the antibody with highhuman homology exhibits both high sequence identity/sequence homologywith human VL, and also that the hypervariable loops in the VL domainexhibit structural homology with human VL.

In one embodiment, the VL domain of the c-Met antibody with high humanhomology may exhibit a sequence identity of 80% or greater, 85% orgreater, 90% or greater, 95% or greater, 97% or greater, or up to 99% oreven 100% with a human VL domain across the framework regions FR1, FR2,FR3 and FR4, and in addition hypervariable loop L1 and hypervariableloop L2 may form a combination of predicted or actual canonical foldstructures which is the same as a canonical fold combination known tooccur naturally in the same human VL domain.

It is, of course, envisaged that VH domains exhibiting high sequenceidentity/sequence homology with human VH, and also structural homologywith hypervariable loops of human VH will be combined with VL domainsexhibiting high sequence identity/sequence homology with human VL, andalso structural homology with hypervariable loops of human VL to provideantibodies with high human homology containing VH/VL pairings (e.gcamelid-derived VH/Vl pairings) with maximal sequence and structuralhomology to human-encoded VH/VL pairings.

“Strict antagonist”—As defined herein, a “strict antagonist” ofHGF-mediated activation of the c-Met receptor has the followingproperties: (1) it is an antagonist of HGF-mediated activation of thec-Met receptor, and (2) it does not exhibit significant intrinsicagonist activity.

As used herein, the term “antagonist of HGF-mediated activation of thec-Met receptor” refers to a molecule, such as a c-Met antibody, which iscapable of inhibiting HGF-dependent c-Met activation/signalling in anappropriate assay system. Effective antagonist antibodies may be capableof inhibiting at least 50%, or at least 60%, or at least 70%, or atleast 75%, or at least 80% of HGF maximal effect in at least one assaysystem capable of detecting HGF-dependent c-Met activation orsignalling, including for example an assay of HGF-dependent c-Metphosphorylation, or an assay of HGF-induced tumour cell proliferation,cell survival assays, etc. A c-Met antibody provided herein may also berecognised as a potent antagonist of HGF-mediated activation of thec-Met receptor if the antagonist activity obtained is at least as potentas that obtained with reference antibody c224G11 (as described in WO2009/007427), which reference antibody is a murine-human chimericantibody of the IgG1 isotype comprising a heavy chain variable domainhaving the amino acid sequence shown as SEQ ID NO:43 and the light chainvariable domain having the amino acid sequence shown as SEQ ID NO:44 anda human constant region which is not hinge-modified, i.e. whichcomprises the wild-type hinge region of human IgG1.

As used herein, the term “intrinsic agonist activity” of a c-Metantibody refers to the ability of the antibody to activate the c-Metreceptor in the absence of the ligand HGF. Intrinsic agonist activitycan be tested in a suitable assay system, for example an assay of c-Metphosphorylation in the presence and absence of HGF. In one embodiment,an antibody exhibits “significant intrinsic agonist activity” if theagonist effect produced in the absence of HGF is greater than 20%, orgreater than 16% of the maximal HGF effect in the same assay system.Conversely, a c-Met antibody is considered not to exhibit significantintrinsic agonist activity if the agonist effect produced in the absenceof HGF is less than 20%, or less than 16%, or less than 10%, or lessthan 5% of the maximal HGF effect in the same assay system. By way ofexample, the antagonist activity and intrinsic agonist activity of ac-Met antibody may be evaluated by performing a cell scatter assay, inthe presence and absence of HGF. “Strict antagonist” antibodies, i.e.lacking significant intrinsic agonist activity, will typically produceno detectable scattering effect in the absence of HGF, but exhibitstrong inhibition of HGF-induced scattering in the same assay system.Intrinsic agonist activity may also be evaluated using thephosphorylation assay described in Example 9 of the present application.The c-Met antibody preferably exhibits less than 20% of the maximal HGFeffect in this assay system.

The c-Met antibodies provided herein are also considered not to exhibitsignificant intrinsic agonist activity if the agonist effect produced inthe absence of HGF is equal to or lower than that obtained withreference antibody c224G11 (as described in WO 2009/007427), whichreference antibody is a murine-human chimeric antibody of the IgG1isotype comprising a heavy chain variable domain having the amino acidsequence shown as SEQ ID NO:43 and the light chain variable domainhaving the amino acid sequence shown as SEQ ID NO:44 and a humanconstant region which is not hinge-modified, i.e. which comprises thewild-type hinge region of human IgG1.

As summarised above, the invention relates to isolated antibodies (whichmay be monoclonal antibodies) having high human homology thatspecifically bind to a human c-Met receptor protein, wherein theantibodies are strict antagonists of HGF-mediated activation of thec-Met receptor. The properties and characteristics of the c-Metantibodies, and antibody fragments, according to the invention will nowbe described in further detail.

c-Met Binding and Affinity

Isolated antibodies having high human homology that specifically bind toa human c-Met receptor protein will typically exhibit a binding affinity(K_(D)) for human c-Met, and more particularly the extracellular domainof human c-Met, of about 10 nM or less, or 1 nM or less, or 0.1 nM orless, or 10 pM or less, and may exhibit a dissociation off-rate forhuman c-Met binding of 10⁻³ s⁻¹ or less, or 10⁻⁴ s⁻¹ or less. Bindingaffinity (K_(D)) and dissociation rate (k_(off)) can be measured usingstandard techniques well known to persons skilled in the art, such asfor example surface plasmon resonance (BIAcore), as described in theaccompanying examples.

The c-Met antibodies described herein exhibit immunological specificityfor binding to human c-Met, and more specifically the extracellulardomain of human c-Met, but cross-reactivity with non-human homologues ofc-Met is not excluded. The binding affinity exhibited with non-humanprimate homologues of c-Met (e.g. rhesus macaque c-Met) is typically1-10, e.g. 5-10, fold lower than the binding affinity for human c-Met.

Antagonist/Agonist Properties

As described elsewhere, the c-Met antibodies provided herein are “strictantagonists” of HGF-mediated activation of the human c-Met receptor,according to the definition given above. The antibodies exhibit potentantagonism of HGF-mediated c-Met activation with minimal agonistactivity. This balance between high antagonist activity and minimalintrinsic agonist activity is critical for therapeutic utility of thec-Met antibodies, since it has been demonstrated previously (WO2010/069765) that the loss of in vitro antagonist activity whichaccompanies the gain in agonist activity in the chimeric form of themurine monoclonal antibody 224G11 can result in significant loss of invivo antagonist activity.

Many in vitro and in vivo assays suitable for testing antagonism ofHGF-mediated c-Met activation and/or agonist activity of c-Metantibodies have been described in the art and would be readily availableto persons of skill in the art (see for example WO 2010/059654, WO2009/07427, WO 2010/069765, Pacchicina et al., JBC, manuscriptM110.134031, September 2010, the technical teachings of which relatingto such assays are to be incorporated herein by reference). Suitableassays include, for example, scatter assay, wound healing assay,proliferation assay, c-Met phosphorylation assay, branchingmorphogenesis assay and assays based on growth inhibition/apoptosis.

Inhibition of HGF-Independent c-Met Activation

The c-Met antibodies provided herein may have the capability to inhibitHGF-independent activation of the c-Met receptor. In vitro assayssuitable for testing HGF-independent activation of the c-Met receptorare described in the accompanying example.

In particular embodiments, the c-Met antibodies may inhibitHGF-independent c-Met receptor activation, and more specifically mayinhibit HGF-independent phosphorylation of c-Met, in the human gastriccarcinoma cell line MKN-45. In particular embodiments, the c-Metantibody may exhibit at least 40%, or at least 50%, or at least 60%, orat least 70% or at least 80% inhibition of HGF-independent c-Metreceptor activation. More specifically the c-Met antibody may exhibit atleast 40%, or at least 50%, or at least 60%, or at least 70% or at least80% inhibition of HGF-independent autophosphorylation c-Met, as measuredby phosphorylation assay, e.g. the phosphorylation assay describedherein performed in the human gastric cell line MKN-45.

The c-Met antibody should preferably exhibit at least the same potencyas reference antibody c224G11 and should preferably exhibit more potentinhibition of HGF-independent activation (autophosphorylation) of c-Metthan the reference antibody c224G11, particularly when measured byphosphorylation assay in MKN-45 cells. Certain of the c-Met antibodiesprovided herein, in particular those comprising the antigen-bindingdomains of 36C4, 48A2 and germlined variants thereof, are shown to bemore potent inhibitors of HGF-independent autophosphorylation of c-Metthan the reference antibody c224G11, whilst still exhibiting comparable(or better) antagonism of HGF-dependent c-Met activation than thereference antibody c224G11 and lower levels of intrinsic agonistactivity than the reference antibody c224G11. As noted elsewhere herein,reference antibody c224G11 (as described in WO 2009/007427) is amurine-human chimeric antibody of the IgG1 isotype comprising a heavychain variable domain having the amino acid sequence shown as SEQ IDNO:181 and the light chain variable domain having the amino acidsequence shown as SEQ ID NO:182 and a human constant region which is nothinge-modified, i.e. which comprises the wild-type hinge region of humanIgG1.

The c-Met antibodies provided herein also exhibit substantially morepotent inhibition of HGF-independent autophosphorylation of c-Met thanthe reference antibody 5D5, which does not display any inhibition inthis assay system.

Inhibition of c-Met Dimerization

The c-Met antibodies provided herein preferably exhibit the capabilityto inhibit dimerization of c-Met receptors, and more particularly theability to inhibit homodimerization and or heterodimerization ofmembrane-bound c-Met receptors present on the cell surface of tumorcells. The ability to inhibit c-Met dimerization is relevant totherapeutic utility of c-Met antibodies, since antibodies which inhibitc-Met dimerization may be useful in the treatment of HGF-independentc-Met-associated cancers, in addition to HGF-dependent activated c-Metcancers. Heterodimerization of c-Met is discussed in Trusolino et al.,Nature Reviews, Molecular Cell Biology., 2010, 11: 834-848.

Assays suitable for testing the ability of c-Met antibodies to inhibitc-Met dimerization have been described in the art and would be readilyavailable to persons of skill in the art (see for example WO 2009/07427and WO 2010/069765, the technical teachings of which relating to suchassays are to be incorporated herein by reference)

In particular embodiments, the c-Met antibodies may exhibit inhibitionof c-Met dimerization in a “Met-addicted” cell line, such as for exampleEBC-1 cells. In particular, the c-Met antibodies may exhibit at least20%, or at least 25%, or at least 30%, or at least 35%, or at least 40%,or at least 45%, or at least 50% inhibition of c-Met (homo)dimerizationin a c-Met-addicted cell line, such as EBC-1 cells. The phenotype of“Met-addiction” occurs in cell lines which exhibit stable chromosomalamplification of the MET oncogene, as described in Smolen et al, PNAS,vol. 103, pp 2316-2321, 2006.

Down-Regulation of Cell-Surface c-Met Protein Expression

The c-Met antibodies provided herein preferably do not inducesignificant down-regulation of cell surface human c-Met protein. Theability of a given c-Met antibody to induce down-regulation of cellsurface human c-Met protein may be assessed using flow cytometry in ac-Met expressing cell line, such as for example MKN-45. In oneembodiment, the c-Met antibodies provided herein are considered not toinduce significant down-regulation of cell surface human c-Met proteinif they induce less than 20%, or less than 15%, or less than 10% or lessthan 5% down-regulation of c-Met protein in this assay system. The c-Metantibodies provided herein are also considered not to induce significantdown-regulation of cell surface human c-Met protein if they induce equalto or lower down-regulation of c-Met protein than the reference antibodyc224G11 described herein.

c-Met antibodies which do not induce significant down-regulation of cellsurface c-Met protein may be particularly suitable for therapeuticapplications which benefit from antibody effector function, i.e. ADCC,CDC, ADCP, and in particular enhanced effector function. The c-Metantibodies which do not induce significant down-regulation of cellsurface c-Met protein are not internalised, and hence may remain boundto cell surface c-Met for significantly longer than c-Met antibodieswhich are internalised. A reduced rate of internalisation (or lack ofsignificant internalisation) is a distinct advantage in c-Met antibodieswhich exhibit effector function via at least one of ADCC, CDC or ADCP.Hence, the c-Met antibodies described herein which exhibit effectorfunction (or enhanced effector function) and which do not inducesignificant down-regulation of cell surface c-Met protein may beparticularly advantageous for certain therapeutic applications, e.g.cancer treatments which benefit from antibody effector function.

c-Met Epitopes

The c-Met antibodies described herein bind to epitopes within theextracellular domain of human c-Met and block binding of HGF to theextracellular domain of c-Met, to varying degrees.

The ability of the c-Met antibodies provided herein to block binding ofHGF to c-Met may be measured by means of a competition assay. Typically,c-Met antibodies block binding of HGF to c-Met with an IC₅₀ of 0.5 nM orless.

The term “epitope” refers to a specific arrangement of amino acidslocated on a peptide or protein to which an antibody or antibodyfragment binds. Epitopes often consist of a chemically active surfacegrouping of molecules such as amino acids or sugar side chains, and havespecific three dimensional structural characteristics as well asspecific charge characteristics. Epitopes can be linear, i.e., involvingbinding to a single sequence of amino acids, or conformational, i.e.,involving binding to two or more sequences of amino acids in variousregions of the antigen that may not necessarily be contiguous.

The c-Met antibodies provided herein may bind to different (overlappingor non-overlapping) epitopes within the extracellular domain of thehuman c-Met protein.

Certain of the c-Met antibodies may bind to epitopes within the SEMAdomain of human c-Met. The SEMA domain is contained within amino acidresidues 1-491 of the mature human c-Met protein (lacking signalsequence, as shown in FIG. 25) and has been recognised in the art ascontaining a binding site for the c-Met ligand HGF.

In one particular embodiment, the c-Met antibody provided herein maybind to an epitope within the peptide 98-VDTYYDDQLISCGSVNRGTCQRHVFPHNHTADIQSEVHCIFSPQIEEPSQCPDCVVSALGAKVLSSVKDRFINFFVGNTINSSYFPDHPLHSISVRRLKETK-199 of human c-Met (SEQ ID NO: 181). In particular, theantibody denoted 36C4, and the germlined variants and affinity variantsthereof, all bind to an epitope within this peptide region of the SEMAdomain. This region of the SEMA domain is significant since it is knownto contain a binding site for the c-Met ligand HGF. Particularlyadvantageous are c-Met antibodies, e,g, antibodies comprising theantigen-binding regions of 36C4 or one of the germlined or affinityvariants thereof, which bind to this peptide epitope within the SEMAdomain of human c-Met and which do not induce significantdown-regulation of cell surface c-Met protein. Such antibodies mayfurther exhibit one or more effector functions selected from ADCC, CDCand ADCP, or enhanced effector function(s).

Other c-Met antibodies provided herein may bind to epitopes within theIPT region of human c-Met. The IPT region is known to include amino acidresidues 544-909 of the mature human c-Met protein lacking the signalpeptide. The IPT region itself is sub-divided into IPT domains 1, 2, 3and 4, as shown in FIG. 25. By means of epitope mapping, it has beendetermined that several of the c-Met antibodies described herein maybind to epitopes within IPT domains 1-2 of human c-Met (IPT-1 comprisesamino acid residues 544-632 of mature human c-Met; IPT-2 comprises aminoacid 633-717 of mature human c-Met), whereas others may bind to epitopeswithin IPT domains 2-3 of human c-Met (IPT-2 comprises amino acidresidues 633-717 of mature human c-Met; IPT-3 comprises amino acidresidues 718-814 of mature human c-Met), and others may bind to epitopeswithin IPT domains 3-4 of c-Met (IPT-3 comprises amino acid residues718-814 of mature human c-Met; IPT-4 comprises amino acid residues815-909 of mature human c-Met).

IPT domains 3-4 have been identified as containing a high affinitybinding site for the ligand HGF (see for example EP 2119448 incorporatedherein by reference) but to date no antibodies capable of binding to IPTdomains 3-4 and antagonising HGF-mediated activation of c-Met have beendescribed. Potent, strictly antagonistic c-Met antibodies binding to theIPT domains, and particularly IPT domains 1-2, 2-3 and 3-4, or to thePSI-IPT region of human c-Met are now provided herein. Crucially, theseantibodies can exhibit high human homology, as defined herein, and canbe provided in recombinant form containing a fully human hinge regionand Fc domain, particularly of the human IgG1 isotype, withoutsignificant loss of antagonist activity or gain of agonist activity. Yetother c-Met antibodies provided herein may bind to conformationalepitopes with part or all of the recognition site within the IPT regionof human c-Met.

A specific therapeutic utility may be achieved by targeting c-Metantibodies to the IPT domains, as defined above, or to junctions betweenIPT domains or to conformational epitopes with all or part of therecognition site within the IPT region of human c-Met.

Other c-Met antibodies provided herein may bind to an epitope within theregion of human c-Met spanning the junction between the PSI domain andIPT domain 1 (PSI-IPT1). The PSI domain of human c-Met spans amino acidresidues 492-543 of the mature human c-Met protein (lacking the signalpeptide), whereas IPT domain 1 spans residues 544-632 of mature humanc-Met. In one particular embodiment, the c-Met antibody may bind to anepitope within the amino acid sequence523-EECLSGTWTQQICLPAIYKVFPNSAPLEGGTRLTI CGWDFGFRRNNKFDLKKTRVLLGNESCTITTLSESTMNTLKCTVGPAMNKHFNMSIIISNGHGTTQYSTFSYVDP-₆₃₃ (SEQ ID NO:136) in the PSI-IPT1 region of the human c-Met protein. In particular,the c-Met antibody denoted herein 48A2, and the germlined variants andaffinity variants of 48A2 described herein, have been demonstrated tobind a conformational epitope within this PSI-IPT1 peptide of humanc-Met. Binding of a c-Met antibody to an epitope within the PSI-IPT1region, and more specifically binding to the epitope bound by antibody48A2 and its variants, may produce an effect both by blocking binding ofthe c-Met ligand HGF to a binding site within the IPT region and bypreventing the conformational change which normally accompanies bindingof HGF to c-Met.

Camelid-Derived c-Met Antibodies

The antibodies of the invention may comprise at least one hypervariableloop or complementarity determining region obtained from a VH domain ora VL domain of a species in the family Camelidae, such as VH and/or VLdomains, or CDRs thereof, obtained by active immunisation of outbredcamelids, e.g. llamas, with a human c-Met antigen.

By “hypervariable loop or complementarity determining region obtainedfrom a VH domain or a VL domain of a species in the family Camelidae” ismeant that that hypervariable loop (HV) or CDR has an amino acidsequence which is identical, or substantially identical, to the aminoacid sequence of a hypervariable loop or CDR which is encoded by aCamelidae immunoglobulin gene. In this context “immunoglobulin gene”includes germline genes, immunoglobulin genes which have undergonerearrangement, and also somatically mutated genes. Thus, the amino acidsequence of the HV or CDR obtained from a VH or VL domain of a Camelidaespecies may be identical to the amino acid sequence of a HV or CDRpresent in a mature Camelidae conventional antibody. The term “obtainedfrom” in this context implies a structural relationship, in the sensethat the HVs or CDRs of the c-Met antibody embody an amino acid sequence(or minor variants thereof) which was originally encoded by a Camelidaeimmunoglobulin gene. However, this does not necessarily imply aparticular relationship in terms of the production process used toprepare the c-Met antibody.

Camelid-derived c-Met antibodies may be derived from any camelidspecies, including inter alia, llama, dromedary, alpaca, vicuna, guanacoor camel.

c-Met antibodies comprising camelid-derived VH and VL domains, or CDRsthereof, are typically recombinantly expressed polypeptides, and may bechimeric polypeptides. The term “chimeric polypeptide” refers to anartificial (non-naturally occurring) polypeptide which is created byjuxtaposition of two or more peptide fragments which do not otherwiseoccur contiguously. Included within this definition are “species”chimeric polypeptides created by juxtaposition of peptide fragmentsencoded by two or more species, e.g. camelid and human

Camelid-derived CDRs may comprise one of the CDR sequences shown as SEQID NOs: 1-21, 71-73 or 83-85 (heavy chain CDRs) or one of the CDRsequences shown as SEQ ID NOs: 22-42, 74-76, 86, 87 or 137-148 (lightchain CDRs).

In one embodiment the entire VH domain and/or the entire VL domain maybe obtained from a species in the family Camelidae. In specificembodiments, the camelid-derived VH domain may comprise the amino acidsequence shown as SEQ ID NO: 45, 46, 47, 48, 49, 50, 51, 77 or 88whereas the camelid-derived VL domain may comprise the amino acidsequence show as SEQ ID NO: 52, 53, 54, 55, 56, 57, 58, 78, 89 or149-164. The camelid-derived VH domain and/or the camelid-derived VLdomain may then be subject to protein engineering, in which one or moreamino acid substitutions, insertions or deletions are introduced intothe camelid amino acid sequence. These engineered changes preferablyinclude amino acid substitutions relative to the camelid sequence. Suchchanges include “humanisation” or “germlining” wherein one or more aminoacid residues in a camelid-encoded VH or VL domain are replaced withequivalent residues from a homologous human-encoded VH or VL domain.

Isolated camelid VH and VL domains obtained by active immunisation of acamelid (e.g. llama) with a human c-Met antigen can be used as a basisfor engineering antigen binding polypeptides according to the invention.Starting from intact camelid VH and VL domains, it is possible toengineer one or more amino acid substitutions, insertions or deletionswhich depart from the starting camelid sequence. In certain embodiments,such substitutions, insertions or deletions may be present in theframework regions of the VH domain and/or the VL domain. The purpose ofsuch changes in primary amino acid sequence may be to reduce presumablyunfavourable properties (e g immunogenicity in a human host (so-calledhumanization), sites of potential product heterogeneity and orinstability (glycosylation, deamidation, isomerisation, etc.) or toenhance some other favourable property of the molecule (e.g. solubility,stability, bioavailability, etc.). In other embodiments, changes inprimary amino acid sequence can be engineered in one or more of thehypervariable loops (or CDRs) of a Camelidae VH and/or VL domainobtained by active immunisation. Such changes may be introduced in orderto enhance antigen binding affinity and/or specificity, or to reducepresumably unfavourable properties, e g immunogenicity in a human host(so-called humanization), sites of potential product heterogeneity andor instability, glycosylation, deamidation, isomerisation, etc., or toenhance some other favourable property of the molecule, e.g. solubility,stability, bioavailability, etc.

Thus, in one embodiment, the invention provides a variant c-Met antibodywhich contains at least one amino acid substitution in at least oneframework or CDR region of either the VH domain or the VL domain incomparison to a camelid-derived VH or VL domain, examples of whichinclude but are not limited to the camelid VH domains comprising theamino acid sequences shown as SEQ ID NO: 45, 46, 47, 48, 49, 50, 51, 77or 88, and the camelid VL domains comprising the amino acid sequencesshow as SEQ ID NO: 52, 53, 54, 55, 56, 57, 58, 78, 89 or 149-164.

In other embodiments, there are provided “chimeric” antibody moleculescomprising camelid-derived VH and VL domains (or engineered variantsthereof) and one or more constant domains from a non-camelid antibody,for example human-encoded constant domains (or engineered variantsthereof). In such embodiments it is preferred that both the VH domainand the VL domain are obtained from the same species of camelid, forexample both VH and VL may be from Lama glama or both VH and VL may befrom Lama pacos (prior to introduction of engineered amino acid sequencevariation). In such embodiments both the VH and the VL domain may bederived from a single animal, particularly a single animal which hasbeen actively immunised with a human c-Met antigen.

As an alternative to engineering changes in the primary amino acidsequence of Camelidae VH and/or VL domains, individual camelid-derivedhypervariable loops or CDRs, or combinations thereof, can be isolatedfrom camelid VH/VL domains and transferred to an alternative (i.e.non-Camelidae) framework, e.g. a human VH/VL framework, by CDR grafting.In particular, non-limiting, embodiments the camelid-derived CDRs may beselected from CDRs having the amino acid sequences shown as SEQ ID NOs:1-21, 71-73 or 83-85 (heavy chain CDRs) or CDRs having the amino acidsequences shown as SEQ ID NOs: 22-42, 74-76, 86, 87 or 137-148 (lightchain CDRs).

c-Met antibodies comprising camelid-derived VH and VL domains, or CDRsthereof, can take various different embodiments in which both a VHdomain and a VL domain are present. The term “antibody” herein is usedin the broadest sense and encompasses, but is not limited to, monoclonalantibodies (including full length monoclonal antibodies), polyclonalantibodies, multispecific antibodies (e.g., bispecific antibodies), solong as they exhibit the appropriate immunological specificity for ahuman c-Met protein. The term “monoclonal antibody” as used hereinrefers to an antibody obtained from a population of substantiallyhomogeneous antibodies, i.e., the individual antibodies comprising thepopulation are identical except for possible naturally occurringmutations that may be present in minor amounts. Monoclonal antibodiesare highly specific, being directed against a single antigenic site.Furthermore, in contrast to conventional (polyclonal) antibodypreparations which typically include different antibodies directedagainst different determinants (epitopes) on the antigen, eachmonoclonal antibody is directed against a single determinant or epitopeon the antigen.

“Antibody fragments” comprise a portion of a full length antibody,generally the antigen binding or variable domain thereof. Examples ofantibody fragments include Fab, Fab′, F(ab′)2, bi-specific Fab's, and Fvfragments, diabodies, linear antibodies, single-chain antibodymolecules, a single chain variable fragment (scFv), domain antibodiesand multispecific antibodies formed from antibody fragments (seeHolliger and Hudson, Nature Biotechnol. 23:1126-36 (2005), the contentsof which are incorporated herein by reference).

In non-limiting embodiments, c-Met antibodies comprising camelid-derivedVH and VL domains, or CDRs thereof, may comprise CH1 domains and/or CLdomains, the amino acid sequence of which is fully or substantiallyhuman. Where the antigen binding polypeptide of the invention is anantibody intended for human therapeutic use, it is typical for theentire constant region of the antibody, or at least a part thereof, tohave fully or substantially human amino acid sequence. Therefore, one ormore or any combination of the CH1 domain, hinge region, CH2 domain, CH3domain and CL domain (and CH4 domain if present) may be fully orsubstantially human with respect to it's amino acid sequence.

Advantageously, the CH1 domain, hinge region, CH2 domain, CH3 domain andCL domain (and CH4 domain if present) may all have fully orsubstantially human amino acid sequence. In the context of the constantregion of a humanised or chimeric antibody, or an antibody fragment, theterm “substantially human” refers to an amino acid sequence identity ofat least 90%, or at least 95%, or at least 97%, or at least 99% with ahuman constant region. The term “human amino acid sequence” in thiscontext refers to an amino acid sequence which is encoded by a humanimmunoglobulin gene, which includes germline, rearranged and somaticallymutated genes. The invention also contemplates polypeptides comprisingconstant domains of “human” sequence which have been altered, by one ormore amino acid additions, deletions or substitutions with respect tothe human sequence, excepting those embodiments where the presence of a“fully human” hinge region is expressly required.

The presence of a “fully human” hinge region in the c-Met antibodies ofthe invention may be beneficial both to minimise immunogenicity and tooptimise stability of the antibody.

As discussed elsewhere herein, it is contemplated that one or more aminoacid substitutions, insertions or deletions may be made within theconstant region of the heavy and/or the light chain, particularly withinthe Fc region Amino acid substitutions may result in replacement of thesubstituted amino acid with a different naturally occurring amino acid,or with a non-natural or modified amino acid. Other structuralmodifications are also permitted, such as for example changes inglycosylation pattern (e.g. by addition or deletion of N- or O-linkedglycosylation sites). Depending on the intended use of the antibody, itmay be desirable to modify the antibody of the invention with respect toits binding properties to Fc receptors, for example to modulate effectorfunction. For example cysteine residue(s) may be introduced in the Fcregion, thereby allowing interchain disulfide bond formation in thisregion. The homodimeric antibody thus generated may have improvedinternalization capability and/or increased complement-mediated cellkilling and antibody-dependent cellular cytotoxicity (ADCC). See Caronet al., J. Exp. Med. 176:1191-1195 (1992) and Shopes, B. J. Immunol.148:2918-2922 (1992). Alternatively, a c-Met antibody can be engineeredwhich has dual Fc regions and may thereby have enhanced complement lysisand ADCC capabilities. See Stevenson et al., Anti-Cancer Drug Design3:219-230 (1989). The invention also contemplates immunoconjugatescomprising an antibody as described herein conjugated to a cytotoxicagent such as a chemotherapeutic agent, toxin (e.g., an enzymaticallyactive toxin of bacterial, fungal, plant or animal origin, or fragmentsthereof), or a radioactive isotope (i.e., a radioconjugate). Fc regionsmay also be engineered for half-life extension, as described by Chan andCarter, Nature Reviews: Immunology, Vol. 10, pp 301-316, 2010,incorporated herein by reference.

Variant c-Met antibodies in which the Fc region is modified by proteinengineering, as described herein, may also exhibit an improvement inefficacy (e.g. in cancer treatment), as compared to an equivalentantibody (i.e. equivalent antigen-binding properties) without the Fcmodification.

In yet another embodiment, the Fc region is modified to increase theability of the antibody to mediate antibody dependent cellularcytotoxicity (ADCC) and/or to increase the affinity of the antibody foran Fcγ receptor by modifying one or more amino acids.

In still another embodiment, the glycosylation of an antibody ismodified. For example, an aglycoslated antibody can be made (i.e., theantibody lacks glycosylation). Glycosylation can be altered to, forexample, increase the affinity of the antibody for the c-Met targetantigen. Such carbohydrate modifications can be accomplished by; forexample, altering one or more sites of glycosylation within the antibodysequence. For example, one or more amino acid substitutions can be madethat result in elimination of one or more variable region frameworkglycosylation sites to thereby eliminate glycosylation at that site.Such aglycosylation may increase the affinity of the antibody forantigen.

Also envisaged are variant c-Met antibodies having an altered type ofglycosylation, such as a hypofucosylated antibody having reduced amountsof fucosyl residues or a non-fucosylated antibody (as described byNatsume et al., Drug Design Development and Therapy, Vol. 3, pp 7-16,2009) or an antibody having increased bisecting GlcNac structures. Suchaltered glycosylation patterns have been demonstrated to increase theADCC activity of antibodies, producing typically 10-fold enhancement ofADCC relative to an equivalent antibody comprising a “native” human Fcdomain. Such carbohydrate modifications can be accomplished by, forexample, expressing the antibody in a host cell with alteredglycosylation enzymatic machinery (as described by Yamane-Ohnuki andSatoh, mAbs 1:3, 230-236, 2009).

Still further embodiments of the c-Met antibodies may be lackingeffector function, either because the Fc portion of the antibody is ofan isotype which naturally lacks effector function, or which exhibitssignificantly less potent effector function than human IgG1, for examplehuman IgG2 or human IgG4, or because the Fc portion of the antibody hasbeen engineered to reduce or substantially eliminate effector function,as described in Armour, K. L., et al., Eur. J. Immunol., 1999, 29:2613-2624.

In still further embodiments the Fc portion of the c-Met antibody may beengineered to facilitate the preferential formation of bispecificantibodies, in which two antibody heavy chains comprising differentvariable domains pair to form the Fc portion of the bispecific antibody.Examples of such modifications include the “knobs-into-hole”modifications described by Ridgway J B, Presta L G, Carter P.,‘Knobs-into-holes’ engineering of antibody CH3 domains for heavy chainheterodimerization. Protein Eng. 1996 July; 9(7):617-21 and Merchant AM, Zhu Z, Yuan J Q, Goddard A, Adams C W, Presta L G, Carter P. Anefficient route to human bispecific IgG. Nat Biotechnol. 1998 July;16(7):677-81.

The invention can, in certain embodiments, encompass chimericCamelidae/human antibodies, and in particular chimeric antibodies inwhich the VH and VL domains are of fully camelid sequence (e.g. Llama oralpaca) and the remainder of the antibody is of fully human sequence.C-Met antibodies can include antibodies comprising “humanised” or“germlined” variants of camelid-derived VH and VL domains, or CDRsthereof, and camelid/human chimeric antibodies, in which the VH and VLdomains contain one or more amino acid substitutions in the frameworkregions in comparison to camelid VH and VL domains obtained by activeimmunisation of a camelid with a human c-Met antigen. Such“humanisation” increases the % sequence identity with human germline VHor VL domains by replacing mis-matched amino acid residues in a startingCamelidae VH or VL domain with the equivalent residue found in a humangermline-encoded VH or VL domain.

c-Met antibodies may also be CDR-grafted antibodies in which CDRs (orhypervariable loops) derived from a camelid antibody, for example ancamelid c-Met antibody raised by active immunisation with human c-Metprotein, or otherwise encoded by a camelid gene, are grafted onto ahuman VH and VL framework, with the remainder of the antibody also beingof fully human origin. Such CDR-grafted c-Met antibodies may containCDRs having the amino acid sequences shown as SEQ ID NOs: 1-21, 71-73 or83-85 (heavy chain CDRs) or CDRs having the amino acid sequences shownas SEQ ID NOs: 22-42, 74-76, 86, 87 or 137-148 (light chain CDRs).

Humanised, chimeric and CDR-grafted c-Met antibodies as described above,particularly antibodies comprising hypervariable loops or CDRs derivedfrom active immunisation of camelids with a human c-Met antigen, can bereadily produced using conventional recombinant DNA manipulation andexpression techniques, making use of prokaryotic and eukaryotic hostcells engineered to produce the polypeptide of interest and includingbut not limited to bacterial cells, yeast cells, mammalian cells, insectcells, plant cells, some of them as described herein and illustrated inthe accompanying examples.

Camelid-derived c-Met antibodies include variants wherein thehypervariable loop(s) or CDR(s) of the VH domain and/or the VL domainare obtained from a conventional camelid antibody raised against humanc-Met, but wherein at least one of said (camelid-derived) hypervariableloops or CDRs has been engineered to include one or more amino acidsubstitutions, additions or deletions relative to the camelid-encodedsequence. Such changes include “humanisation” of the hypervariableloops/CDRs. Camelid-derived HVs/CDRs which have been engineered in thismanner may still exhibit an amino acid sequence which is “substantiallyidentical” to the amino acid sequence of a camelid-encoded HV/CDR. Inthis context, “substantial identity” may permit no more than one, or nomore than two amino acid sequence mis-matches with the camelid-encodedHV/CDR. Particular embodiments of the c-Met antibody may containhumanised variants of the CDR sequences shown as SEQ ID NOs: 1-21, 71-73or 83-85 (heavy chain CDRs) and/or humanised variants of the CDRsequences shown as SEQ ID NOs: 22-42, 74-76, 86, 87 or 137-148 (lightchain CDRs).

The camelid-derived c-Met antibodies provided herein may be of anyisotype. Antibodies intended for human therapeutic use will typically beof the IgA, IgD, IgE IgG, IgM type, often of the IgG type, in which casethey can belong to any of the four sub-classes IgG1, IgG2a and b, IgG3or IgG4. Within each of these sub-classes it is permitted to make one ormore amino acid substitutions, insertions or deletions within the Fcportion, or to make other structural modifications, for example toenhance or reduce Fc-dependent functionalities.

Humanisation (Germlining) of Camelid-Derived VH and VL Domains Camelidconventional antibodies provide an advantageous starting point for thepreparation of antibodies with utility as human therapeutic agents dueto the following factors, discussed in U.S. Ser. No. 12/497,239 which isincorporated herein by reference:1) High % sequence homology between camelid VH and VL domains and theirhuman counterparts;2) High degree of structural homology between CDRs of camelid VH and VLdomains and their human counterparts (i.e. human-like canonical foldstructures and human-like combinations of canonical folds).

The camelid (e.g. llama) platform also provides a significant advantagein terms of the functional diversity of the c-Met antibodies which canbe obtained.

The utility of c-Met antibodies comprising camelid VH and/or camelid VLdomains for human therapy can be improved still further by“humanisation” or “germlining” of natural camelid VH and VL domains, forexample to render them less immunogenic in a human host. The overall aimof humanisation is to produce a molecule in which the VH and VL domainsexhibit minimal immunogenicity when introduced into a human subject,whilst retaining the specificity and affinity of the antigen bindingsite formed by the parental VH and VL domains.

One approach to humanisation, so-called “germlining”, involvesengineering changes in the amino acid sequence of a camelid VH or VLdomain to bring it closer to the sequence of a human VH or VL domain

Determination of homology between a camelid VH (or VL) domain and humanVH (or VL) domains is a critical step in the humanisation process, bothfor selection of camelid amino acid residues to be changed (in a givenVH or VL domain) and for selecting the appropriate replacement aminoacid residue(s).

An approach to humanisation of camelid conventional antibodies has beendeveloped based on alignment of a large number of novel camelid VH (andVL) domain sequences, typically somatically mutated VH (or VL) domainswhich are known to bind a target antigen, with human germline VH (or VL)sequences, human VH (and VL) consensus sequences, as well as germlinesequence information available for llama pacos.

The following passages outline the principles which can be applied to(i) select “camelid” amino acid residues for replacement in acamelid-derived VH or VL domain or a CDR thereof, and (ii) selectreplacement “human” amino acid residues to substitute in, whenhumanising any given camelid VH (or VL) domain. This approach can beused to prepare humanised variants of camelid-derived CDRs having theamino acid sequences shown as SEQ ID NOs: 1-21, 71-73 or 83-85 (heavychain CDRs) or having the amino acid sequences shown as SEQ ID NOs:22-42, 74-76, 86, 87 or 137-148 (light chain CDRs), and also forhumanisation of camelid-derived VH domains having the sequences shown asSEQ ID NOs: 45-51, 77 or 88 and of camelid-derived VL domains having thesequences shown as SEQ ID NOs: 52-58, 78, 89 or 149-164.

Step 1. Select human (germline) family and member of this family thatshows highest homology/identity to the mature camelid sequence to behumanised. A general procedure for identifying the closest matchinghuman germline for any given camelid VH (or VL) domain is outlinedbelow.Step 2. Select specific human germline family member used to germlineagainst. Preferably this is the germline with the highest homology oranother germline family member from the same family.Step 3. Identify the preferred positions considered for germlining onthe basis of the table of amino acid utilisation for the camelidgermline that is closest to the selected human germline.Step 4. Try to change amino acids in the camelid germline that deviatefrom the closest human germline; germlining of FR residues is preferredover CDR residues.a. Preferred are positions that are deviating from the selected humangermline used to germline against, for which the amino acid found in thecamelid sequence does not match with the selected germline and is notfound in other germlines of the same subclass (both for V as well as forJ encoded FR amino acids).b. Positions that are deviating from the selected human germline familymember but which are used in other germlines of the same family may alsobe addressed in the germlining process.c. Additional mismatches (e.g. due to additional somatic mutations)towards the selected human germline may also be addressed.The following approach may be used to determine the closest matchinghuman germline for a given camelid VH (or VL) domain:

Before analyzing the percentage sequence identity between Camelidae andhuman germline VH and VL, the canonical folds may first be determined,which allows the identification of the family of human germline segmentswith the identical combination of canonical folds for H1 and H2 or L1and L2 (and L3). Subsequently the human germline family member that hasthe highest degree of sequence homology with the Camelidae variableregion of interest may be chosen for scoring sequence homology. Thedetermination of Chothia canonical classes of hypervariable loops L1,L2, L3, H1 and H2 can be performed with the bioinformatics toolspublicly available on webpage www.bioinf.org.uk/abs/chothia.html.page.The output of the program shows the key residue requirements in adatafile. In these datafiles, the key residue positions are shown withthe allowed amino acids at each position. The sequence of the variableregion of the antibody is given as input and is first aligned with aconsensus antibody sequence to assign the Kabat numbering scheme. Theanalysis of the canonical folds uses a set of key residue templatesderived by an automated method developed by Martin and Thornton (Martinet al., J. Mol. Biol. 263:800-815 (1996)). The boundaries of theindividual framework regions may be assigned using the IMGT numberingscheme, which is an adaptation of the numbering scheme of Chothia(Lefranc et al., NAR 27: 209-212 (1999); http://imgt.cines.fr).

With the particular human germline V segment known, which uses the samecombination of canonical folds for H1 and H2 or L1 and L2 (and L3), thebest matching family member in terms of sequence homology can bedetermined. The percentage sequence identity between Camelidae VH and VLdomain framework amino acid sequences and corresponding sequencesencoded by the human germline can be determined using bioinformatictools, but manual alignment of the sequences could also be used. Humanimmunoglobulin sequences can be identified from several protein databases, such as VBase (http://vbase.mrc-cpe.cam.ac.uk/) or thePluckthun/Honegger database(http://www.bioc.unizh.ch/antibody/Sequences/Germlines. To compare thehuman sequences to the V regions of Camelidae VH or VL domains asequence alignment algorithm such as available via websites likewww.expasy.ch/tools/#align can be used, but also manual alignment canalso be performed with a limited set of sequences. Human germline lightand heavy chain sequences of the families with the same combinations ofcanonical folds and with the highest degree of homology with theframework regions 1, 2, and 3 of each chain may be selected and comparedwith the Camelidae variable region of interest; also the FR4 is checkedagainst the human germline JH and JK or JL regions.

Note that in the calculation of overall percent sequence homology theresidues of FR1, FR2 and FR3 are evaluated using the closest matchsequence from the human germline family with the identical combinationof canonical folds. Only residues different from the closest match orother members of the same family with the same combination of canonicalfolds are scored (NB—excluding any primer-encoded differences). However,for the purposes of humanization, residues in framework regionsidentical to members of other human germline families, which do not havethe same combination of canonical folds, can be considered forhumanization, despite the fact that these are scored “negative”according to the stringent conditions described above. This assumptionis based on the “mix and match” approach for humanization, in which eachof FR1, FR2, FR3 and FR4 is separately compared to its closest matchinghuman germline sequence and the humanized molecule therefore contains acombination of different FRs as was done by Qu and colleagues (Qu etla., Clin. Cancer Res. 5:3095-3100 (1999)) and Ono and colleagues (Onoet al., Mol. Immunol. 36:387-395 (1999)).

By way of example only, it is contemplated that humanised variants of VHdomains having the amino acid sequences shown as SEQ ID Nos: 45-51, 77or 88 may include variants in which the amino acid residue(s) occurringat one or more of the positions listed in the following table is/arereplaced with an amino acid residue which occurs at the equivalentposition in a human VH domain, e.g. a human germline-encoded VH domain.Appropriate amino acid substitutions can be derived by following thegeneral protocol for humanisation described above.

TABLE 3 List of amino acid residue positions which may be substitutedduring germlining (humanisation) of the listed VH domains. For eachnamed VH domain, the listed amino acid residues are numbered accordingto the Kabat numbering system. VH FR1 CDR1 FR2 CDR2 FR3 CDR3 FR4 38H101, 7, 9, 11, 54*, 55* 69, 71, 78, 108 SEQ ID 49 12, 13, 28 80, 82a, 8540B8 11, 12, 13 69, 71, 78, 108 SEQ ID 50 80, 82b 20A11 30 74, 83, 84108 SEQ ID 47 12G4 11, 12, 19, 48 74, 83, 84 108 SEQ ID 45 30 13E6 10,30 48 74, 82a, 108 SEQ ID 46 83, 84, 85, 93 34H7 10, 23, 24, 74, 83, 84,108 SEQ ID 77 29 94 36C4 2, 5, 23, 40, 48 54*, 55* 67, 68, 71, 108 SEQID 51 30 81, 84, 85 20F1 29, 30 48 67, 68, 71, 108 SEQ ID 48 81, 83, 84,85 *note substitution of residues 54 and 55 is for the purpose ofremoving a deamidation site, not for human germlining as such.

By way of example only, it is contemplated that humanised variants of VLdomains having the amino acid sequences shown as SEQ ID Nos: 52-58, 78,89 or 137-148 may include variants in which the amino acid residue(s)occurring at one or more of the positions listed in the following tableis/are replaced with an amino acid residue which occurs at theequivalent position in a human VL domain, e.g. a human germline-encodedVL domain. Appropriate amino acid substitutions can be derived byfollowing the general protocol for humanisation described above.

TABLE 4 List of amino acid residue positions which may be substitutedduring germlining (humanisation) of the listed VL domains. For eachnamed VL domain, the listed amino acid residues are numbered accordingto the Kabat numbering system. VL FR1 CDR1 FR2 CDR2 FR3 CDR3 FR4 38H109, 11, 12, 39, 40, 43, 78, 80, 83 100 SEQ ID 52 13, 15, 18, 45, 49 1940B8 9, 11, 12, 39, 40, 43, 78, 80, 83 106 SEQ ID 53 13, 15, 18, 45 1920A11 14, 15, 17, 69, 70, 74, 100 SEQ ID 58 18, 19 76, 80 12G4 14, 15,17, 69, 70, 74, SEQ ID 56 18 76, 80 13E6 14, 15, 17, 69, 70, 74, SEQ ID57 18 76, 80 34H7 11, 14, 18, 38 66, 69, 74 103 SEQ ID 78 22 36C4 3, 8,17, 39, 47, 49 58, 72, 75, 103 SEQ ID 55 18 80 20F1 17, 18 39, 42, 4758, 80, 84, 103, 105 SEQ ID 54 87 48A2 7, 9, 11, 39, 40, 43, 68, 77, 78,100, 107 SEQ ID 89 12, 13, 15, 45 80, 83 17, 18, 19Cross-Competing Antibodies

Monoclonal antibodies or antigen-binding fragments thereof that“cross-compete” with the molecules disclosed herein are those that bindhuman c-Met at site(s) that are identical to, or overlapping with, thesite(s) at which the present c-Met antibodies bind. Competing monoclonalantibodies or antigen-binding fragments thereof can be identified, forexample, via an antibody competition assay. For example, a sample ofpurified or partially purified human c-Met can be bound to a solidsupport. Then, an antibody compound or antigen binding fragment thereofof the present invention and a monoclonal antibody or antigen-bindingfragment thereof suspected of being able to compete with such inventionantibody compound are added. One of the two molecules is labelled. Ifthe labelled compound and the unlabeled compound bind to separate anddiscrete sites on c-Met, the labelled compound will bind to the samelevel whether or not the suspected competing compound is present.However, if the sites of interaction are identical or overlapping, theunlabeled compound will compete, and the amount of labelled compoundbound to the antigen will be lowered. If the unlabeled compound ispresent in excess, very little, if any, labelled compound will bind. Forpurposes of the present invention, competing monoclonal antibodies orantigen-binding fragments thereof are those that decrease the binding ofthe present antibody compounds to c-Met by about 50%, about 60%, about70%, about 80%, about 85%, about 90%, about 95%, or about 99%. Detailsof procedures for carrying out such competition assays are well known inthe art and can be found, for example, in Harlow and Lane (1988)Antibodies, A Laboratory Manual, Cold Spring Harbor Laboratory Press,Cold Spring Harbor, N.Y., pages 567-569, ISBN 0-87969-314-2. Such assayscan be made quantitative by using purified antibodies. A standard curveis established by titrating one antibody against itself, i.e., the sameantibody is used for both the label and the competitor. The capacity ofan unlabeled competing monoclonal antibody or antigen-binding fragmentthereof to inhibit the binding of the labeled molecule to the plate istitrated. The results are plotted, and the concentrations necessary toachieve the desired degree of binding inhibition are compared.

Polynucleotides Encoding c-Met Antibodies

The invention also provides a polynucleotide molecules encoding thec-Met antibodies of the invention, also expression vectors containing anucleotide sequences which encode the c-Met antibodies of the inventionoperably linked to regulatory sequences which permit expression of theantigen binding polypeptide in a host cell or cell-free expressionsystem, and a host cell or cell-free expression system containing thisexpression vector.

In particular embodiments, the polynucleotide encoding the c-Metantibody of the invention thereof may comprise one or more of thepolynucleotide sequences shown as SEQ ID NOs:59-70, 79-82, 90, 91,122-135 or 165-180, which sequences encode VH or VL domains of c-Metantibodies, or a variant sequence which encodes a functional VH or VLdomain of a c-Met antibody, wherein said variant sequence exhibits atleast 80%, 85%, 90%, 95%, 97% or 99% sequence identity when optimallyaligned to one of SEQ ID NOs: 59-70, 79-82, 90, 91, 122-135 or 165-180.In this context, % sequence identity between two polynucleotidesequences may be determined by comparing these two sequences aligned inan optimum manner and in which the polynucleotide sequence to becompared can comprise additions or deletions with respect to thereference sequence for an optimum alignment between these two sequences.The percentage of identity is calculated by determining the number ofidentical positions for which the nucleotide residue is identicalbetween the two sequences, by dividing this number of identicalpositions by the total number of positions in the comparison window andby multiplying the result obtained by 100 in order to obtain thepercentage of identity between these two sequences. For example, it ispossible to use the BLAST program, “BLAST 2 sequences” (Tatusova et al,“Blast 2 sequences—a new tool for comparing protein and nucleotidesequences”, FEMS Microbiol Lett. 174:247-250) available on the sitehttp://www.ncbi.nlm.nih.gov/gorf/bl2.html, the parameters used beingthose given by default (in particular for the parameters “open gappenalty”: 5, and “extension gap penalty”: 2; the matrix chosen being,for example, the matrix “BLOSUM 62” proposed by the program), thepercentage of identity between the two sequences to be compared beingcalculated directly by the program.

Polynucleotide molecules encoding the c-Met antibodies of the inventioninclude, for example, recombinant DNA molecules. The terms “nucleicacid”, “polynucleotide” or a “polynucleotide molecule” as used hereininterchangeably and refer to any DNA or RNA molecule, either single- ordouble-stranded and, if single-stranded, the molecule of itscomplementary sequence. In discussing nucleic acid molecules, a sequenceor structure of a particular nucleic acid molecule may be describedherein according to the normal convention of providing the sequence inthe 5′ to 3′ direction. In some embodiments of the invention, nucleicacids or polynucleotides are “isolated.” This term, when applied to anucleic acid molecule, refers to a nucleic acid molecule that isseparated from sequences with which it is immediately contiguous in thenaturally occurring genome of the organism in which it originated. Forexample, an “isolated nucleic acid” may comprise a DNA molecule insertedinto a vector, such as a plasmid or virus vector, or integrated into thegenomic DNA of a prokaryotic or eukaryotic cell or non-human hostorganism. When applied to RNA, the term “isolated polynucleotide” refersprimarily to an RNA molecule encoded by an isolated DNA molecule asdefined above. Alternatively, the term may refer to an RNA molecule thathas been purified/separated from other nucleic acids with which it wouldbe associated in its natural state (i.e., in cells or tissues). Anisolated polynucleotide (either DNA or RNA) may further represent amolecule produced directly by biological or synthetic means andseparated from other components present during its production.

For recombinant production of a c-Met antibody according to theinvention, a recombinant polynucleotide encoding it may be prepared(using standard molecular biology techniques) and inserted into areplicable vector for expression in a chosen host cell, or a cell-freeexpression system. Suitable host cells may be prokaryote, yeast, orhigher eukaryote cells, specifically mammalian cells. Examples of usefulmammalian host cell lines are monkey kidney CV1 line transformed by SV40(COS-7, ATCC CRL 1651); human embryonic kidney line (293 or 293 cellssubcloned for growth in suspension culture, Graham et al., J. Gen.Virol. 36:59 (1977)); baby hamster kidney cells (BHK, ATCC CCL 10);Chinese hamster ovary cells/-DHFR (CHO, Urlaub et al., Proc. Natl. Acad.Sci. USA 77:4216 (1980)); mouse sertoli cells (TM4, Mather, Biol.Reprod. 23:243-251 (1980)); mouse myeloma cells SP2/0-AG14 (ATCC CRL1581; ATCC CRL 8287) or NS0 (HPA culture collections no. 85110503);monkey kidney cells (CV1 ATCC CCL 70); African green monkey kidney cells(VERO-76, ATCC CRL-1587); human cervical carcinoma cells (HELA, ATCC CCL2); canine kidney cells (MDCK, ATCC CCL 34); buffalo rat liver cells(BRL 3A, ATCC CRL 1442); human lung cells (W138, ATCC CCL 75); humanliver cells (Hep G2, HB 8065); mouse mammary tumor (MMT 060562, ATCCCCL51); TRI cells (Mather et al., Annals N.Y. Acad. Sci. 383:44-68(1982)); MRC 5 cells; FS4 cells; and a human hepatoma line (Hep G2), aswell as DSM's PERC-6 cell line. Expression vectors suitable for use ineach of these host cells are also generally known in the art.

It should be noted that the term “host cell” generally refers to acultured cell line. Whole human beings into which an expression vectorencoding an antigen binding polypeptide according to the invention hasbeen introduced are explicitly excluded from the definition of a “hostcell”.

Antibody Production

In an important aspect, the invention also provides a method ofproducing a c-Met antibody of the invention which comprises culturing ahost cell (or cell free expression system) containing polynucleotide(e.g. an expression vector) encoding the c-Met antibody under conditionswhich permit expression of the c-Met antibody, and recovering theexpressed c-Met antibody. This recombinant expression process can beused for large scale production of c-Met antibodies according to theinvention, including monoclonal antibodies intended for humantherapeutic use. Suitable vectors, cell lines and production processesfor large scale manufacture of recombinant antibodies suitable for invivo therapeutic use are generally available in the art and will be wellknown to the skilled person.

Therapeutic Utility of c-Met Antibodies

The c-Met antibodies provided herein can be used in the treatment ofboth HGF-dependent and HGF-independent cancers.

Inappropriate activation of c-Met can be induced by specific geneticlesions, transcriptional upregulation or ligand-dependent autocrine orparacrine mechanisms (Comoglio et al, Nature Reviews Drug Discovery,7:504-516, 2008). HGF-dependent and HGF independent cancers that can betreated with the c-Met antibodies include, but are not limited togastric carcinomas, oesophageal carcinomas, medulloblastomas, livermetastases from colon carcinoma, papillary renal carcinomas, head andneck squamous cell carcinomas, thyroid, ovarian, pancreatic, protrate,renal-cell, hepatocellular, breast and colorectal carcinomas,glioblastomas, rhabdomyosarcomas and osteosarcomas.

The term “treating” or “treatment” means slowing, interrupting,arresting, controlling, stopping, reducing severity of a symptom,disorder, condition or disease, but does not necessarily involve a totalelimination of all disease-related symptoms, conditions or disorders.

For human therapeutic use the c-Met antibodies described herein may beadministered to a human subject in need of treatment in an “effectiveamount”. The term “effective amount” refers to the amount or dose of ac-Met antibody which, upon single or multiple dose administration to ahuman patient, provides therapeutic efficacy in the treatment ofdisease. Therapeutically effective amounts of the c-Met antibody cancomprise an amount in the range of from about 0.1 mg/kg to about 20mg/kg per single dose. A therapeutic effective amount for any individualpatient can be determined by the healthcare professional by monitoringthe effect of the c-Met antibody on a biomarker, such as cell surfacec-Met in tumour tissues, or a symptom such as tumour regression, etc.The amount of antibody administered at any given time point may bevaried so that optimal amounts of c-Met antibody, whether employed aloneor in combination with any other therapeutic agent, are administeredduring the course of treatment.

It is also contemplated to administer the c-Met antibodies describedherein, or pharmaceutical compositions comprising such antibodies, incombination with any other cancer treatment, as a combination therapy.

Pharmaceutical Compositions

The scope of the invention includes pharmaceutical compositions,containing one or a combination of c-Met antibodies of the invention, orantigen-binding fragments thereof, formulated with one or more apharmaceutically acceptable carriers or excipients. Such compositionsmay include one or a combination of (e.g., two or more different) c-Metantibodies. For example, a pharmaceutical composition of the inventioncan comprise a combination of antibodies that bind to different epitopeson human c-Met, e.g. an antibody binding to the SEMA domain of humanc-Met combined with an antibody which binds within the PSI-IPT domain ofhuman c-Met.

Techniques for formulating monoclonal antibodies for human therapeuticuse are well known in the art and are reviewed, for example, in Wang etal., Journal of Pharmaceutical Sciences, Vol. 96, pp 1-26, 2007.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be further understood with reference to the followingexperimental examples and the accompanying Figures in which:

FIG. 1. The MKN-45-specific immune response in pre-immune (day 0) andpost-immune (day 45) sera from llamas immunized with MKN-45 cells, asmeasured by Flow cytometry.

FIG. 2. The immune response to recombinant c-Met in pre-immune (day 0)and post-immune (day 45) sera from llamas immunized with MKN-45 cells,as measured by ELISA.

FIG. 3. Competition assay showing Fab-containing periplasmic extractscompeting with N-terminally biotinylated HGF (25 ng/ml) for binding toc-Met captured via the C-terminal Fc portion.

FIGS. 4A-4B. ELISA illustrating antibody 40B8 binding to c-Met IPT1-2domain (FIG. 4A) and 36C4 binding to c-Met SEMA domain (FIG. 4B).

FIG. 5. The results of a scatter assay using HPAF cells demonstratinginhibition of HGF-induced scattering by antibody 38H10 in adose-dependent manner (upper panel). No agonistic effects were observedcompared to the medium only control.

FIG. 6. An ELISA based competition assay illustrating the degree ofcompetition between antibodies and HGF for binding c-Met at differentantibody concentrations. Percentage competition was calculated comparedto control antibodies.

FIGS. 7A-7B: Proliferation assay using BxPC3 cells. Chimeric 224G11 isc224G11. (FIG. 7A) Antibody-induced proliferation as a percentage of themaximum effect at 75 ng/ml of HGF. (FIG. 7B) The effect of antibodies onHGF-induced proliferation as compared to the maximum effect at 75 ng/mlof HGF.

FIGS. 8A-8B: Agonism as measured in a phosphorylation assay using NSCLCA549 cells. The percentage of c-Met phosphorylation induced byantibodies 38H10 and 48A2 (FIG. 8A) and 36C4 (FIG. 8B) is expressed as apercentage of phosphorylation induced by 100 ng/ml HGF. Murine 224G11(m224G11) and chimeric 224G11 (c224G11) were included as positivecontrols and antibody U16 was included as a negative control.

FIG. 9: Antagonism as measured in a phosphorylation assay using A549cells. Inhibition of HGF-induced c-Met phosphorylation by antibodies isindicated as a percentage compared to the maximum effect of 100 ng/mlHGF alone in A549 cells. Chimeric 224G11 (c224G11) was included aspositive control and antibody U16 as a negative control.

FIG. 10: Blocking of HGF-independent activation measured in aphosphorylation assay using MKN-45 cells. Inhibition ofautophosphorylation in MKN-45 cells by antibodies was compared to thenegative control U16.1, where inhibition by U16.1 was set as 0%.

FIG. 11: Antibody-induced ADCC in MKN-45 cells using Dead-Cell ProteaseKit (CytoTox-Glo™ Cytotoxicity Assay). The percentage lysis is expressedas specific lysis compared to the negative isotype control.

FIG. 12: Potelligent™ 36C4-induced ADCC in NCI-H441 cells expressed aspercentage lysis of the cells as measured using a ⁵¹Cr release assay.

FIG. 13. In vivo effect of ADCC-enhanced 36C4 on MKN-45 xenografts withtwice weekly injections of mAb.

FIGS. 14A-14B. Surface Plasmon Resonance of 36C4 and 48A2 for binding tonon-overlapping epitopes. Binding is observed to the Met:48A2 complexonly (FIG. 14A) and to the Met:36C4 complex only (FIG. 14B).

FIG. 15. Alignment of human and Llama glama c-Met amino acid sequences.X54559: SEQ ID NO:207. Lama glama c-Met: SEQ ID NO:208.

FIGS. 16A-16B. Domain mapping of mAbs using chimeric c-Met ECD. 36C4binding to the human c-Met (WT) and the human/llama IPT1-4 indicatingbinding to the SEMA-PSI region (FIG. 16A). Binding of mAb 13E6 to thehuman c-Met and to the llama/human IPT1-4 (FIG. 16B).

FIG. 17. Inhibition of autophosphorylation using combinations of c-MetmAbs in MKN-45 cells.

FIGS. 18A-18B. The results of a phosphorylation assay using combinationsof c-Met mAbs in NSCLC A549 cells showing agonistic effects (FIG. 18A)and antagonistic effects (FIG. 18B). U16 is the isotype control andc224G11 the positive control.

FIG. 19. In vivo U87 MG xenograft experiment testing the effects ofadministering 30 mg/kg 36C4 on tumour growth versus the effect ofadministering 30 mg/kg of c224G11.

FIGS. 20A-20B. Phosphorylation assay using germlined 36C4 mAbs on A549cells showing agonism (FIG. 20A) and antagonism (FIG. 20B). U16 is theisotype control and c224G11 the positive control.

FIG. 21. PBS stability of germlined 36C4 variants at varioustemperatures. Functionality tests were performed using Surface PlasmonResonance on germlined 36C4 mAbs after incubation in PBS at 4° C., RTand 37° C. for up to 56 days.

FIGS. 22A-22B. Thermotolerance of germlined 36C4 (FIG. 22A) and 48A2(FIG. 22B). Functionality investigated using Surface Plasmon Resonanceafter incubation at different temperatures for 1 h.

FIGS. 23A-23B. Schematic illustration of the structure of chimericllama-human c-Met constructs prepared for: (FIG. 23A) peptide mapping ofmAb (e.g. 36C4) binding to the SEMA domain of c-Met. Light grey shadingindicates llama c-Met sequence (LS); dark grey shading indicates humanc-Met sequence (hS). The relative positions of the signal sequence, SEMAdomain, PSI domain and IPT domains 1, 2, 3 and 4 are indicated; (FIG.23B) peptide mapping of mAb (e.g. 48A2) binding to the PSI-IPT1 domainof c-Met. Light grey shading indicates llama c-Met sequence; dark greyshading indicates human c-Met sequence. The relative positions of thesignal sequence, SEMA domain, PSI domain and IPT domains 1, 2, 3 and 4are indicated.

FIG. 24. An assay for down-regulation of total c-Met protein on thesurface of MKN-45 cells following treatment with various c-Met mAbs atconcentrations of 1 μg/ml or 10 μg/ml. Results are expressed as apercentage total of c-Met down-regulation.

FIG. 25. The amino acid sequence of the extracellular portion of humanc-Met, illustrating the positions of the SEMA domain and IPT domains.X54559: SEQ ID NO:209.

INCORPORATION BY REFERENCE

Various publications are cited in the foregoing description andthroughout the following examples, each of which is incorporated byreference herein in its entirety.

EXAMPLES

The invention will be further understood with reference to the followingnon-limiting experimental examples.

Example 1: Immunization of Llamas

Immunization of llamas and harvesting of peripheral blood lymphocytes(PBLs), as well as the subsequent extraction of RNA and amplification ofantibody fragments, were performed as described by De Haard andcolleagues (De Haard H, et al., JBC. 274:18218-30, 1999). Eight llamaswere immunized with the human gastric cell line MKN-45 over-expressingc-Met (DMSZ, ACC409)(c-Met over-expression was confirmed by Flowcytometry using PE conjugated anti-HGFR antibody (R&D systems, cat noFAB3582P)). Another two llamas were immunized with lung cancer cell lineNCI-H441 cells. The llamas were immunized with intramuscular injectionsin the neck once per week for a period of six weeks. Approximately 10⁷cells were injected into the neck muscles and Freund's incompleteadjuvant was injected in a second region located a few centimetres fromthe injection site of the cells.

Blood samples of 10 ml were collected pre- and post immunization toinvestigate the immune response. Three to four days after the lastimmunization, 400 ml blood was collected and total RNA extracted fromPBLs prepared using a Ficoll-Paque gradient and the method described byChomczynski P et al. (Anal. Biochem. 162: 156-159, 1987). The averageRNA yield was 450 μg. The extracted RNA was then used for random cDNAsynthesis and PCR amplification of the V-regions of the heavy and thelight chains (Vλ and Vκ) in order to construct the Fab-containingphagemid libraries as described by De Haard H, et al. (Biol. Chem. 274,1999) The resultant libraries showed good levels of diversity (1-7×10⁸).

The immune response to MKN-45 cells or NCI-H441 cells was investigatedusing Flow cytometry. 100 μl/well of the diluted sera were added ontothe cells (2×10⁵ cells/well) and incubated for 30 minutes at 4° C. Afterwashing with PBS and 1% BSA, 0.1 μg/100 μl/well of FITC-conjugated goatanti-llama antibody (BETHYL, # A160-100F) was added and incubated for 30minutes at 4° C. After washing with PBS and 1% BSA the results were readon a FACS Calibur and the mean fluorescence was plotted against thedilutions of the sera (FIG. 1).

The specific immune response to c-Met was determined using an ELISA withimmobilized recombinant c-Met (R&D systems, 358-MT/CF) using pre- andpost-immune sera (Day 0 and Day 45 respectively). Llama IgG1 bound toimmobilised c-Met was detected using a mouse anti-llama IgG1 (Daley L P,et al. Clin. Diagn. Lab Immunol. 12: 380-386, 2005) and a HRP-conjugateddonkey anti-mouse antibody (Jackson). FIG. 2 shows the immune responseof 4 of the 10 immunized llamas. A similar immune response was observedfor the other 4 llamas immunized with the MKN-45 cells, but not for theNCI-H441 cell immunized llamas.

Example 2: Selections and Screenings of c-Met-Specific Fabs

Phage expressing Fabs were produced according to standard protocols andfurther selected on immobilized recombinant dimeric c-Met (R&D systems,358-MT/CF) or recombinant extracellular domain of c-Met. Total elutionof the c-Met binding phage with trypsin was performed according tostandard phage display protocols.

Two to four rounds of selection were performed to enrich forc-Met-specific Fabs expressed by the phage. Individual colonies wereisolated and periplasmic fractions (penis) were produced by IPTGinduction from all the libraries according to standard protocols.

Screening of the c-Met-specific Fabs for competition with mature HGF forbinding to immobilized c-Met was performed using an ELISA-basedcompetition assay. 2 μg/ml of goat anti-human Fcγ antibody (Jackson) wasimmobilized on a maxisorb plate and, after blocking with 1% casein inPBS for 2 h, 100 ng/ml recombinant dimeric c-Met was added and incubatedfor 1 h at room temperature. After washing, 50 μl of the Fab containingpenis was added and allowed to bind to the captured c-Met, before 25ng/ml of N-terminally biotinylated mature HGF (R&D systems, 294-HGN/CF)was added. N-terminal biotinylation was performed according to protocolprovided by Thermo Scientific with a 5-fold excess of NHS-LC biotin in a50 mM phosphate buffer (pH 6.5) at 4° C. for 24 h. Biotinylated matureHGF was incubated at room temperature for 1 h before washing andaddition of horseradish-conjugated streptavidin (strep-HRP) andincubated for an additional hour. TMB was added and the plate read at620 nm. A non-relevant periplasmic extract and a 50-fold excess of cold(non-biotinylated) HGF was included as a positive control in all theplates. An example of Fab-containing penis competing with HGF is givenin FIG. 3.

HGF-competing clones were sequenced in the VH and the VL regions anddivided into VH families based on the sequence of the CDR3 in the VH.These VH families were further tested with Surface Plasmon Resonance(SPR) for dissociation (k_(off)) and recognition of SEMA-PSI or theextracellular domain of c-Met (Decoy). Between 1000-2000 RU of dimericc-Met, SEMA-PSI or Decoy c-Met was immobilised on a VIA chip with aminecoupling in sodium acetate buffer (pH 4.5). The Fab-containing peniswere added with a flow rate of 30 μl/min and Fabs were considered to bebinding if an increase of the RU was observed. The k_(off) was measuredfor 2 minutes for each sample. Table 8 summarizes the domain recognitionand k_(off) for different VH families.

Several VH families recognized the SEMA-PSI domain, whereas othersrecognized only the Decoy c-Met. The Fabs had k_(off) in the range of10⁻³ s⁻¹-10⁻⁴ s⁻¹, with the best (12G4) having a k_(off) of 1.3×10⁻⁴s⁻¹.

The VH and VL domains of antagonistic clones were fused with humanconstant IgG1 domains and with human Cκ or Cλ domains and produced asbivalent monoclonal antibodies in the system described in patentapplication WO 2009/145606 with expression yields of 15-30 μg/ml afterprotein A purification.

TABLE 5 CDR sequences of antagonist antibodies and germlined variants(According to Kabat numbering) SEQ SEQ SEQ mAb CDR1 ID NO CDR2 ID NOCDR3 ID NO VH 12G4 DYAMT   1 TISWNDINTYYAESMKD  2 RRDNYYGTSGEYDY   313E6 DYVMN   4 AINWNGGSTYYAESMKG  5 DTVVSGNGY   6 20A11 DYAMS   7AISWNGSSTYYAESMKG  8 DLIGSHDY   9 20F1 GNYYAWS  10 VIAYDGSTYYSPSLKS 11GPGWYSGSRNDY  12 38H10 MNSID  13 RIDPEDGGTKYAQKFQG 14 VDDYYLGYDY  1540B8 NYVID  16 RIDPENGGTRYAQKFQG 17 LEDYELAYDY  18 36C4 TNYYYWS  19VIAYDGSTDYSPSLKS 20 DVRVIATGWATANALDA  21 34H7 SYAMS  71GIYKGGGPKYANSVKG 72 SGYGSSLGDFGS  73 48A2 MNSID  13 RIDPEDGGTKYAQKFQG 14VDDYYLGYDY  15 55A12-54E TNYYYWS  19 VIAYEGSTDYSPSLKS 83DVRVIATGWATANALDA  21 53E2-54E TNYYYWS  19 VIAYEGSTDYSPSLKS 83DVRVIATGWATANALDA  21 53E3 TNYYYWS  19 VIAYEGSTDYSPSLKS 83DVRVIATGWATANALDA  21 53A11 TNYYYWS  19 VIAYDASTDYSPSLKS 84DVRVIATGWATANALDA  21 56F3 MNSID  13 RIDPEEGGTKYAQKFQG 85 VDDYYLGY  1556D8 MNSID  13 RIDPEEGGTKYAQKFQG 85 VDDYYLGY  15 56B1 MNSID  13RIDPEEGGTKYAQKFQG 85 VDDYYLGY  15 56E9 MNSID  13 RIDPEEGGTKYAQKFQG 85VDDYYLGY  15 56E5 MNSID  13 RIDPEEGGTKYAQKFQG 85 VDDYYLGY  15 56E1 MNSID 13 RIDPEEGGTKYAQKFQG 85 VDDYYLGY  15 56G5 MNSID  13 RIDPEEGGTKYAQKFQG85 VDDYYLGY  15 Vκ (V kappa) 38H10 KSSQSVLWRSNQKNYLA  22 WASIRES 23QQGYSFPYT  24 40B8 KSSQSVLLSSNQKNYLA  25 WASTRES 26 QQGVSFPLT  27 48A2KSSQSVLFSSNQKNYLA  86 WASIRES 23 QQGYSFPYS  87 56F3 KSSQSVLFSSNQKNYLA 86 WASIRES 23 QQGYSFPYS  87 56D8 KSSQSVLFSSNQKNYLA  86 WASIRES 23QQGYSFPYS  87 56B1 KSSQSVLFSSNQKNYLA  86 WASIRES 23 QQGYSFPYS  87 56E9KSSQSVLFSSNQKNYLA  86 WASIRES 23 QQGYSFPYS  87 56E5 KSSQSVLFSSNQKNYLA 86 WASIRES 23 QQGYSFPYS  87 56E1 KSSQSVLFSSNQKNYLA  86 WASIRES 23QQGYSFPYS  87 56G5 KSSQSVLFSSNQKNYLA  86 WASIRES 23 QQGYSFPYS  87 48A1KSSQSVLWRSNQKNYLA  22 WASIRES 23 QQGYSFPYT  24 48A11 KSSQSVLYNPNQKSYLA137 WASTRES 26 QQGYSFPYS  87 48B8 KSSQSVLYTSNHKNYLA 138 WASTRES 26QQGWSFPYS 139 48D2 KSSQSVLYNSNQKNYLA 140 WASTRES 26 QQGWSFPYT 141 48B6KSSQSVLYGSNQKNYLA 142 WASTRES 26 QQGWSFPYT 141 48C8 KSSQSVLYNSNQKNYLA140 WASTRES 26 QQGWSFPYT 141 48E5 KSSQSVLYNSNQKNYLA 140 WASTRES 26QQGWSFPYT 141 48D7 KSSQSVLFSSNQKNYLA  86 WASTRES 26 QQGYSFPYS  87 48E2KSSQSVLWSSNQKNYLA 143 WASTRES 26 QQGYSFPYS  87 Vλ (V lambda) 20F1TGTNSDVGYGNYVS  28 DVNRRAS 29 ASYRSANNAV   30 36C4 AGTSSDVGYGNYVS  31AVSYRAS 32 ASYRSSNNAAV   33 12G4 AGTSSDIGNYNYVS  34 EVNKRPS 35ASYRSSNNVV   36 13E6 AGTSSDIGDYNYVS  37 DVNKRAS 38 ASYRSRNDYA   39 20A11AGTSSDVGYGNYVS  40 AVSTRAS 41 ASYRSSNNYA   42 34H7 TGSSSNIGGGYYLS  74SNINRAS 75 SSWDDSVSGPV   76 55A12-54E AGTSSDVGYGNYVS  31 AVSYRAS 32ASYRSSNNAAV   33 53E2-54E AGTSSDVGYGNYVS  31 AVSYRAS 32 ASYRSSNNAAV   3353E3 AGTSSDVGYGNYVS  31 AVSYRAS 32 ASYRSSNNAAV   33 53A11 AGTSSDVGYGNYVS 31 AVSYRAS 32 ASYRSSNNAAV   33 49A1 AGTSSDVGYGNYVS  31 AVSYRAS 32ASYRSSNNAAV   33 49D2 AGTSTDVGYGNYVS 144 AVSYRAS 32 ASYRSSNNAAV   3349G3 AGTSTDVGYGNYVS 144 AVSYRAS 32 ASYRSSNNAAV   33 49D3 AGTSTDVGYGNYVS144 AVSYRAS 32 ASYRSSNKNAV  145 49A11 AGTSSDVGYGNYVS  31 AVSYRAS 32ASYRITNRHSV  146 49C4 AGTSTDVGYGNYVS 144 AVSYRAS 32 ASYRRSTNVGV  14749E11 AGTSTDVGYGNYVS 144 AVSYRAS 32 ASYRTSNNVAV  148

TABLE 6 Amino acid sequences of the heavy and light chain variabledomains of selected antagonistic Fabs and affinity variantsHeavy chain variable domain sequences >12G4_VH (SEQ ID NO: 45)QLQLVESGGGMAQPGGSLKLSCAASGFTFDDYAMTWVRQAPGKGLEWLSTISWNDINTYYAESMKDRFTISRDNAKNTLYLQMNSTFSEDTAVYYCAKRRDNYYGTSGEYDYWGQGTQVTVSS >13E6_VH (SEQ ID NO: 46)QVQLQESGGDLVQPGGSLRLSCAASGFTFDDYVMNWVRQAPGKGLEWISAINWNGGSTYYAESMKGRFTISRDNAKNTLYLQMYSLQSDDTAVYYCVKDTVVSGNGYWGQGTQVTVSS >20A11_VH (SEQ ID NO: 47)QVQLVESGGGLVQPGGSLRLSCAASGFTFDDYAMSWVRQAPGKGLEWVSAISWNGSSTYYAESMKGRFTISRDNAKNTLYLQMNSLKSEDTAVYYCAKDLIGSHDYWGQGTQVTVSS >20F1_VH (SEQ ID NO: 48)EVQVQESGPGLVKPSQTLSLTCTVSGGSMTGNYYAWSWIRQPPGKGLEWMGVIAYDGSTYYSPSLKSRTSISRDTSKNQFSLQLSSVSPEDTAVYYCARGPGWYSGSRNDYWGQGTQVTVSS >38H10_VH (SEQ ID NO: 49)EVQLVQPGVELRNPGASVKVSCKASGYIFTMNSIDWVRQAPGQGLEWMGRIDPEDGGTKYAQKFQGRVTFTADTSTSTAYVELNSLRSEDTAVYYCARVDDYYLGYDYWGQGTQVTVSS >40B8_VH (SEQ ID NO: 50)EVQLVQPGAELRNPGASVKVSCKASGYTFTNYVIDWVRQAPGQGLEWMGRIDPENGGTRYAQKFQGRVTFTADTSTSTAYVELSNLRSEDTAVYYCARLEDYELAYDYWGQGTQVTVSS >36C4_VH (SEQ ID NO: 51)QVQLVESGPGLVKPSQTLSLTCAVSGGSITTNYYYWSWIRQSPGKGLEWMGVIAYDGSTDYSPSLKSRTSISRDTSKNQFSLQLSSVTPEDTAVYYCARDVRVIATGWATANALDAWGQGTLVTVSS >48A2_VH (SEQ ID NO: 49)EVQLVQPGVELRNPGASVKVSCKASGYIFTMNSIDWVRQAPGQGLEWMGRIDPEDGGTKYAQKFQGRVTFTADTSTSTAYVELNSLRSEDTAVYYCARVDDYYLGYDYWGQGTQVTVSS >36C4Q_VH (SEQ ID NO: 88)QVQLVESGPGLVKPSQTLSLTCAVSGGSITTNYYYWSWIRQSPGKGLEWMGVIAYDGSTDYSPSLKSRTSISRDTSKNQFSLQLSSVTPEDTAVYYCARDVRVIATGWATANALDAWGQGTQVTVSS >34H7_VH (SEQ ID NO: 77)ELQLVESGGALVQPGGSLRLSCVESGFTFSSYAMSWVRQAPGKGLEWVSGIYKGGGPKYANSVKGRFTISRDNAKNTLYLQMNSLKPEDTAVYYCAKSGYGSSLGDEGSWGQGTQVTVSSLight chain variable domain sequences >38H10_VK (SEQ ID NO: 52)EIVMTQSPSSVTASAGEKVTINCKSSQSVLWRSNQKNYLAWYQQRLGQSPRLLISWASIRESGVPDRFSGSGSTTDFTLTISSFQPEDAAVYYCQQGYSFPYTFGSGTRLEIK >40B8_VK (SEQ ID NO: 53)DIVMTQTPSSVTASAGEKVTINCKSSQSVLLSSNQKNYLAWYQQRLGQSPRLLIYWASTRESGVPDRFSGSGSTTDFTLTISSFQPEDAAVYYCQQGVSFPLTFGQGTKVELK >48A2_VK (SEQ ID NO: 89)DIVMTQTPTSVTASAGDKVTINCKSSQSVLFSSNQKNYLAWYQQRLGQSPRLLIYWASIRESGVPDRFSGSGSATDFTLTISNFQPEDAAVYYCQQGYSFPYSFGSGTRLEIR >20F1_VL (SEQ ID NO: 54)QSALTQPPSVSGSPGKTVTISCTGTNSDVGYGNYVSWYQQLPGMAPKLLIYDVNRRASGIADRFSGSKSGNTASLTISGLQSEDEGDYHCASYRSANNAVFGGGTHLFVL >36C4_VL (SEQ ID NO: 55)QSVLTQPPSVSGSPGKTVTISCAGTSSDVGYGNYVSWYQQLPGTAPKLLIFAVSYRASGIPDRFSGSKSGNTAFLTISGLQSEDEADYYCASYRSSNNAAVFGGGTHLTVL >12G4_VL (SEQ ID NO: 56)QSALTQPPSVSGTLGKTVTISCAGTSSDIGNYNYVSWYQQLPGTAPKLLIYEVNKRPSGIPDRFSGSKSGNTASLSISGLQSEDEADYYCASYRSSNNVVFGGGTKLTVL >13E6_VL (SEQ ID NO: 57)QSVLTQPPSVSGTLGKTVTISCAGTSSDIGDYNYVSWYQQLPGTAPKLLIYDVNKRASGIPDRFSGSKSGNTASLSISGLQSEDEADYYCASYRSRNDYAFGGGTKLTVL >20A11_VL (SEQ ID NO: 58)QAVLTQPPSVSGTLGKTLTISCAGTSSDVGYGNYVSWYQQLPGTAPKLLIYAVSTRASGIPDRFSGSKSGNTASLTISGLQSEDEADYYCASYRSSNNYAFGAGTKLTVL >34H7_VL (SEQ ID NO: 78)QAGLTQLSSMSGSPGQTVTITCTGSSSNIGGGYYLSWYQHLPGTAPKLLIYSNINRASGVPDRFSGSTSGISASLTITGLQAEDEADYYCSSWDDSVSGPVFGGGTSLTVL >48A1_VK (SEQ ID NO: 149)EIVMTQSPSSVTASAGEKVTINCKSSQSVLWRSNQKNYLAWYQQRLGQSPRLLISWASIRESGVPDRFSGSGSTTDFTLTISSFQPEDAAVYYCQQGYSFPYTFGSGTRLEIK >48A11_VK (SEQ ID NO: 150)DIVMTQTPSSVTAAVGEKVAINCKSSQSVLYNPNQKSYLAWYQQRPGQSPRLLIYWASTRESGVPDRFSGSGSTTDFALTISSFQPEDAAVYYCQQGYSFPYSFGSGTRLEIR >48B8_VK (SEQ ID NO: 151)DVVMTQSPSSVTASVGEKVTINCKSSQSVLYTSNHKNYLAWYQQRLGQSPRLLIYWASTRESGVPDRFSGSGSTTDFTLTISSFQPEDAAVYYCQQGWSFPYSFGSGTRLEIK >48D2_VK (SEQ ID NO: 152)DIVMTQTPSSVTASAGEKVTINCKSSQSVLYNSNQKNYLAWYQQRLGQSPRLLIYWASTRESGVPDRFSGSGSTTDFTLTISSFQPEDAAVYYCQQGWSFPYTFGSGTRTFIK >48B6_VK (SEQ ID NO: 153)DIQLTQSPSSVTASAGEKVTINCKSSQSVLYGSNQKNYLAWYQQRLGQSPRLLIYWASTRESGVPDRFSGSGSTTDFTLTISSFQPEDAAVYYCQQGWSFPYTFGSGTRLEIK >48C8_VK (SEQ ID NO: 154)DIQLTQSPSSVTVSVGEKVTINCKSSQSVLYNSNQKNYLAWYQQRLGQSPRLLIYWASTRESGVPDRFSGSGSTTDFTLTISSFQPEDAAVYYCQQGWSFPYTFGSGTRLEIK >48E5_VK (SEQ ID NO: 155)DIQMTQSPSSVTASAGEKVTINCKSSQSVLYNSNQKNYLAWYQQRLGQSPRLLIYWASTRESGVPDRFSGSGSTTDFTLTISSFQPEDAAVYYCQQGWSFPYTFGSGTRLEIK >48D7_VK (SEQ ID NO: 156)DIVMTQTPASVTASAGEKVTINCKSSQSVLFSSNQKNYLAWYQQRVGQSPRLLIYWASTRESGVPDRFSGSGSTTDFTLTISNFQPEDAAVYYCQQGYSFPYSFGSGTRLEIR >48E2_VK (SEQ ID NO: 157)DVVMTQSPSSVTASAGEKVTINCKSSQSVLWSSNQKNYLAWYQQRVGQSPRLLIYWASTRESGVPDRFSGSGSTTDFTLTISNFQPEDAAVYYCQQGYSFPYSFGSGTRLEIR >49A1_VL (SEQ ID NO: 158)QSVLTQPPSVSGSPGKTVTISCAGTSSDVGYGNYVSWYQQLPGTAPKLLIFAVSYRASGIPDRFSGSKSGNTAFLTISGLQSEDEADYYCASYRSSNNAAVFGGGTHLTVL >49D2_VL (SEQ ID NO: 159)QSVLTQPPSVSGTLGKTLTISCAGTSTDVGYGNYVSWYQQLPGTAPKLLIFAVSYRASGIPDRFSGSKSGNTAFLTISGLQSEDEADYYCASYRSSNNAAVFGGGTHLTVL >49G3_VL (SEQ ID NO: 160)QSALTQPPSVSGTLGKTLTISCAGTSTDVGYGNYVSWYQQLPGTAPKLLIFAVSYRASGIPDRFSGSKSGNTAFLTISGLQSEDEADYYCASYRSSNNAAVFGGGTHLTVL >49D3_VL (SEQ ID NO: 161)LPVLTQPPSVSGTLGKTLTISCAGTSSDVGYGNYVSWYQQLPGTAPKLLIYAVSYRASGIPDRFSGSKSGNTASLSISGLQSEDEADYYCASYRSSNKNAVFGGGTHLTVL >49A11_VL (SEQ ID NO: 162)QSALTQPPSVSGSPGKTVTISCAGTSSDVGYGNYVSWYQKLPGTAPKLLIYAVSYRASGIPDRFSGSRSGNTASLTISGLQSEDEADYYCASYRITNRHSVFGGGTHLTVL >49C4_VL (SEQ ID NO: 163)QSALTQPPSVSGTLGKTVTISCAGTSSDVGYGNYVSWYQKLPGTAPKLLIYAVTYRASGIPDRFSGSKSGNTASLTISGLQSEDEADYYCASYRRSTNVGVFGGGTHLTVL >49E11_VL (SEQ ID NO: 164)QAVLTQPPSVSGTLGKTVTISCAGTSSDVGYGNYVSWYQKLPGTAPKLLIYAVSYRASGIPDRFSGSKSGNTASLTISGLQSEDEADYHCASYRTSNNVAVFGGGTKLTVL

TABLE 7 Nucleotide sequences encoding heavy and light chain variabledomains of selected antagonistic FabsHeavy chain variable domain sequences >36C4_VH (SEQ ID NO: 59)CAGGTGCAGCTCGTGGAGTCGGGCCCAGGCCTGGTGAAGCCCTCGCAGACACTCTCCCTCACCTGCGCTGTCTCTGGTGGCTCCATCACAACCAACTATTACTACTGGAGCTGGATTCGCCAGTCCCCAGGGAAGGGGCTGGAGTGGATGGGAGTCATAGCTTATGATGGCAGCACTGACTACAGCCCATCCCTCAAGAGCCGCACTTCCATCTCCAGGGACACGTCCAAGAACCAGTTCTCCCTGCAGCTGAGCTCTGTGACCCCTGAGGACACGGCCGTGTATTACTGTGCCAGAGATGTAAGGGTAATCGCTACGGGTTGGGCTACTGCCAATGCTTTGGACGCATGGGGCCAGGGGACCCTGGTCACTGTCTCCTCAGC >48A2_VH (SEQ ID NO: 60)GAGGTCCAGCTGGTGCAGCCAGGGGTTGAACTGAGAAACCCTGGGGCATCAGTGAAGGTCTCCTGCAAGGCTTCTGGATACATTTTCACCATGAACTCAATAGACTGGGTGCGACAGGCCCCTGGACAAGGGCTTGAGTGGATGGGAAGAATTGACCCTGAAGATGGTGGCACAAAGTATGCACAGAAGTTCCAGGGCAGAGTCACCTTCACTGCAGACACGTCCACCAGCACAGCCTACGTGGAGCTGAACAGTCTGAGATCTGAGGACACGGCCGTGTATTACTGTGCGAGAGTAGATGACTATTACCTAGGGTATGACTACTGGGGCCAGGGGACCCAGGTCACCGTCTCCTCA >36C4Q_VH (SEQ ID NO: 90)CAGGTGCAGCTCGTGGAGTCGGGCCCAGGCCTGGTGAAGCCCTCGCAGACACTCTCCCTCACCTGCGCTGTCTCTGGTGGCTCCATCACAACCAACTATTACTACTGGAGCTGGATTCGCCAGTCCCCAGGGAAGGGGCTGGAGTGGATGGGAGTCATAGCTTATGATGGCAGCACTGACTACAGCCCATCCCTCAAGAGCCGCACTTCCATCTCCAGGGACACGTCCAAGAACCAGTTCTCCCTGCAGCTGAGCTCTGTGACCCCTGAGGACACGGCCGTGTATTACTGTGCCAGAGATGTAAGGGTAATCGCTACGGGTTGGGCTACTGCCAATGCTTTGGACGCATGGGGCCAGGGGACCCAGGTCACCGTGTCCTCA >38H10_VH (SEQ ID NO: 60)GAGGTCCAGCTGGTGCAGCCAGGGGTTGAACTGAGAAACCCTGGGGCATCAGTGAAGGTCTCCTGCAAGGCTTCTGGATACATTTTCACCATGAACTCAATAGACTGGGTGCGACAGGCCCCTGGACAAGGGCTTGAGTGGATGGGAAGAATTGACCCTGAAGATGGTGGCACAAAGTATGCACAGAAGTTCCAGGGCAGAGTCACCTTCACTGCAGACACGTCCACCAGCACAGCCTACGTGGAGCTGAACAGTCTGAGATCTGAGGACACGGCCGTGTATTACTGTGCGAGAGTAGATGACTATTACCTAGGGTATGACTACTGGGGCCAGGGGACCCAGGTCACCGTCTCCTCA >40B8_VH (SEQ ID NO: 61)GAGGTCCAGCTGGTGCAGCCAGGGGCTGAGCTGAGAAACCCTGGGGCATCAGTGAAGGTCTCCTGCAAGGCTTCTGGATACACCTTCACCAACTACGTCATAGACTGGGTACGACAGGCCCCTGGACAAGGGCTTGAGTGGATGGGAAGAATTGACCCTGAAAACGGTGGCACGAGGTATGCACAGAAGTTCCAGGGCAGAGTCACCTTCACTGCAGACACGTCCACCAGCACAGCCTACGTGGAGTTGAGCAATCTGAGATCTGAGGACACGGCCGTGTATTACTGTGCAAGACTGGAAGACTACGAATTGGCTTATGACTACTGGGGCCAGGGGACCCAGGTCACCGTCTCTTCAG >20A11_VH (SEQ ID NO: 62)CAGGTGCAGCTCGTGGAGTCTGGGGGAGGCTTGGTGCAGCCTGGGGGGTCTCTGAGACTCTCCTGTGCAGCCTCTGGATTCACTTTTGATGATTATGCCATGAGCTGGGTCCGACAGGCTCCAGGGAAGGGGCTGGAGTGGGTCTCAGCTATTAGCTGGAATGGTAGTAGCACATACTATGCAGAATCCATGAAGGGCCGATTCACCATCTCCAGAGACAACGCCAAGAACACGCTGTATCTGCAAATGAACAGTCTGAAATCTGAGGACACGGCCGTGTATTACTGTGCAAAAGATCTAATAGGATCCCATGACTACTGGGGCCAGGGGACCCAGGTCACCGTGTCCTCA >34H7_VH (SEQ ID NO: 79)GAGTTGCAGCTGGTGGAGTCTGGGGGAGCCTTGGTGCAGCCTGGGGGGTCTCTGAGACTCTCCTGTGTAGAGTCTGGATTCACCTTCAGTAGTTATGCCATGAGCTGGGTCCGCCAGGCTCCAGGAAAGGGGCTCGAGTGGGTCTCAGGTATTTATAAAGGTGGTGGTCCAAAATATGCAAACTCCGTGAAGGGCCGATTCACCATCTCCAGAGACAACGCCAAGAACACGCTGTATCTGCAAATGAACAGCCTGAAACCTGAGGACACGGCCGTTTATTACTGTGCAAAATCGGGGTACGGTAGTAGCCTTGGGGACTTTGGTTCCTGGGGCCAGGGGACCCAGGTCACCGTCTCCTCG >12G4_VH (SEQ ID NO: 63)CAGTTGCAGCTGGTGGAGTCTGGGGGAGGCATGGCGCAGCCTGGGGGGTCTCTGAAACTCTCCTGTGCAGCCTCTGGATTCACTTTCGATGATTATGCCATGACCTGGGTCCGACAGGCTCCAGGGAAGGGGCTGGAGTGGCTCTCAACTATTAGCTGGAATGACATTAACACATACTATGCAGAATCCATGAAGGACCGATTCACCATCTCCAGAGACAACGCCAAGAACACGCTGTATCTGCAAATGAACAGTCTCGAATCTGAGGACACGGCCGTGTATTACTGTGCAAAACGTAGGGATAATTACTACGGGACTTCCGGGGAGTATGACTACTGGGGCCAGGGGACCCAGGTCACCGTCTCCTCA >13E6_VH (SEQ ID NO: 64)CAGGTGCAGCTGCAGGAGTCGGGGGGAGACTTGGTGCAGCCGGGGGGGTCTCTGAGACTCTCCTGTGCAGCCTCTGGATTCACTTTTGATGATTATGTCATGAACTGGGTCCGACAGGCTCCAGGGAAGGGGCTGGAGTGGATCTCAGCTATTAACTGGAATGGTGGTAGCACATACTATGCAGAATCCATGAAGGGCCGATTCACCATCTCCAGAGACAACGCCAAGAACACGCTGTATCTGCAAATGTACAGTCTGCAATCTGACGACACGGCCGTGTATTACTGTGTAAAAGATACGGTAGTGTCTGGTAATGGCTACTGGGGCCAGGGGACCCAGGTCACCGTGTCCTCA >20F1_VH (SEQ ID NO: 80)GAGGTGCAGGTGCAGGAGTCGGGCCCAGGCCTGGTGAAGCCCTCGCAGACGCTCTCCCTCACCTGCACTGTCTCTGGTGGCTCCATGACAGGCAACTATTATGCTTGGAGCTGGATCCGCCAGCCCCCAGGGAAGGGGCTGGAGTGGATGGGAGTCATAGCTTATGATGGCAGCACTTACTACAGCCCATCCCTCAAGAGCCGCACTTCTATCTCCAGGGACACGTCCAAGAACCAGTTCTCCCTGCAGTTGAGCTCTGTGAGCCCTGAGGACACGGCCGTGTATTACTGTGCCAGAGGCCCAGGGTGGTATAGTGGTAGCAGGAATGACTACTGGGGCCAGGGGACCCAGGTCACCGTCTCCTCALight chain variable domain sequences >36C4_VL (SEQ ID NO: 65)CAGTCTGTGTTGACGCAGCCTCCCTCCGTGTCTGGGTCTCCAGGAAAGACGGTCACCATCTCCTGTGCAGGAACCAGCAGTGATGTTGGGTATGGAAACTATGTCTCCTGGTACCAGCAGCTCCCAGGCACGGCCCCCAAACTCCTGATCTTTGCAGTCAGCTATCGAGCCTCAGGGATCCCTGATCGCTTCTCTGGCTCCAAGTCAGGCAACACGGCCTTTTTGACCATCTCTGGGCTCCAGTCCGAGGACGAGGCTGATTATTACTGTGCCTCATATAGAAGCAGCAACAATGCTGCTGTGTTCGGCGGAGGGACCCATCTGACCGTCCTG >48A2_VK (SEQ ID NO: 91)GATATTGTGATGACCCAGACTCCCACCTCCGTGACTGCATCTGCAGGAGACAAGGTCACCATCAATTGTAAGTCCAGCCAGAGTGTGTTATTCAGCTCCAACCAGAAAAACTACTTAGCTTGGTACCAGCAGAGACTTGGACAGTCTCCTAGGCTGCTCATCTACTGGGCTTCCATCCGAGAATCGGGGGTTCCTGATCGATTCAGCGGCAGTGGGTCCGCAACAGATTTCACGCTAACCATCAGCAACTTCCAGCCTGAAGACGCGGCAGTATATTACTGCCAGCAGGGTTATAGTTTTCCATATAGTTTCGGCAGTGGGACCAGGCTGGAAATCAGA >38H10_VK (SEQ ID NO: 66)GAAATTGTGATGACGCAGTCTCCCAGCTCCGTGACTGCGTCTGCAGGAGAGAAGGTCACCATCAATTGTAAGTCCAGCCAGAGTGTGTTATGGCGCTCCAACCAGAAAAACTACTTAGCTTGGTACCAGCAGAGACTTGGACAGTCTCCTAGGCTGCTCATCAGCTGGGCATCCATCCGAGAATCGGGGGTTCCTGATCGATTCAGCGGCAGTGGGTCCACAACAGATTTCACTCTTACCATCAGCAGCTTCCAGCCTGAAGACGCGGCAGTGTATTACTGCCAACAGGGTTATAGTTTTCCATATACATTCGGCAGTGGGACCAGGCTGGAAATCAAA >34H7_VL (SEQ ID NO: 81)GCACAGGCAGGGCTGACTCAGCTGTCCTCCATGTCTGGATCCCCGGGCCAGACGGTCACCATCACCTGCACAGGAAGCAGCAGCAACATCGGGGGTGGTTATTATTTGAGCTGGTACCAACATCTGCCAGGAACGGCCCCCAAACTCCTGATCTACAGTAACATCAATAGGGCCTCGGGGGTCCCGGACCGCTTCTCTGGCTCCACGTCGGGCATCTCGGCCTCCCTGACTATCACTGGGCTCCAGGCTGAGGACGAGGCTGACTATTACTGTTCATCCTGGGATGACAGCGTCAGTGGTCCTGTGTTCGGCGGAGGGACCAGTCTGACCGTCCTC >12G4_VL (SEQ ID NO: 67)CAGTCTGCCCTGACTCAGCCTCCCTCCGTGTCCGGAACTCTGGGAAAGACGGTCACCATCTCTTGCGCTGGAACCAGCAGTGACATTGGGAACTATAACTATGTCTCCTGGTATCAACAGCTCCCAGGAACAGCCCCCAAACTCCTGATATATGAGGTCAATAAACGACCCTCAGGGATCCCTGATCGCTTCTCTGGCTCCAAGTCAGGCAACACGGCCTCCCTGAGCATCTCTGGGCTCCAGTCTGAGGACGAGGCTGATTATTACTGTGCCTCATATAGAAGCAGCAACAATGTTGTGTTCGGCGGAGGGACCAAGCTGACCGTCCTC >13E6_VL (SEQ ID NO: 68)CAGTCTGTGTTGACGCAGCCTCCCTCCGTGTCCGGAACTCTGGGAAAGACGGTCACCATCTCCTGCGCTGGAACCAGCAGTGACATTGGGGACTATAACTATGTCTCCTGGTATCAACAGCTCCCAGGAACGGCCCCCAAACTCCTGATATATGACGTCAATAAACGAGCCTCAGGGATCCCTGATCGCTTCTCTGGCTCCAAGTCAGGCAACACGGCCTCCCTGAGCATCTCTGGGCTCCAGTCTGAGGACGAGGCTGATTATTACTGTGCCTCATATAGAAGCAGGAACGATTATGCCTTCGGCGGAGGGACCAAGCTGACCGTCCTC >20A11_VL (SEQ ID NO: 69)CAGGCTGTGCTGACTCAGCCTCCCTCCGTGTCCGGAACTCTGGGAAAGACGCTCACCATCTCCTGCGCTGGAACCAGCAGTGATGTTGGATACGGAAACTATGTCTCCTGGTACCAACAGCTCCCAGGCACGGCCCCCAAACTCCTGATCTATGCAGTCAGCACTCGAGCCTCAGGGATCCCTGATCGCTTCTCTGGCTCCAAGTCAGGCAACACGGCCTCCCTGACCATCTCTGGGCTCCAGTCTGAGGACGAGGCTGATTATTACTGTGCCTCATATAGAAGCAGCAACAATTATGCGTTCGGCGCAGGGACCAAGCTGACCGTCCTC >40B8_VK (SEQ ID NO: 70)GATATTGTGATGACCCAGACTCCCAGCTCCGTGACTGCGTCTGCAGGAGAGAAGGTCACCATCAATTGTAAGTCCAGCCAGAGTGTGTTATTGAGCTCCAACCAGAAAAACTACTTAGCTTGGTACCAGCAGAGACTTGGACAGTCTCCTAGGCTGCTCATCTACTGGGCATCCACCCGAGAATCGGGGGTTCCTGATCGATTCAGCGGCAGTGGGTCCACAACAGATTTCACTCTTACCATCAGCAGCTTCCAGCCTGAAGACGCGGCAGTGTATTACTGCCAGCAGGGTGTAAGTTTTCCACTTACGTTCGGCCAGGGGACCAAGGTGGAACTCAAA >20F1_VL (SEQ ID NO: 82)CAGTCTGCCCTGACTCAGCCTCCCTCCGTGTCTGGGTCTCCAGGAAAGACGGTCACCATCTCCTGTACAGGAACCAACAGTGATGTTGGGTACGGAAACTATGTCTCCTGGTACCAGCAGCTCCCAGGAATGGCCCCCAAACTCCTGATATATGACGTCAATAGACGGGCCTCAGGGATCGCTGATCGCTTCTCTGGCTCCAAGTCTGGCAACACGGCCTCCCTGACCATTTCTGGGCTCCAGTCTGAGGACGAGGGTGATTATCATTGTGCCTCATATAGAAGTGCCAACAATGCTGTGTTCGGCGGAGGGACCCATCTGTTCGTCCTG >48A1_VK (SEQ ID NO: 165)GAAATTGTGATGACGCAGTCTCCCAGCTCCGTGACTGCGTCTGCAGGAGAGAAGGTCACCATCAATTGTAAGTCCAGCCAGAGTGTGTTATGGCGCTCCAACCAGAAAAACTACTTAGCTTGGTACCAGCAGAGACTTGGACAGTCTCCTAGGCTGCTCATCAGCTGGGCATCCATCCGAGAATCGGGGGTTCCTGATCGATTCAGCGGCAGTGGGTCCACAACAGATTTCACTCTTACCATCAGCAGCTTCCAGCCTGAAGACGCGGCAGTGTATTACTGCCAACAGGGTTATAGTTTTCCATATACATTCGGCAGTGGGACCAGGCTGGAAATCAAA >48A11_VK (SEQ ID NO: 166)GATATTGTGATGACCCAGACTCCTAGCTCCGTGACTGCGGCTGTAGGAGAGAAGGTCGCTATCAACTGTAAGTCCAGCCAGAGCGTGTTATATAACCCCAACCAGAAAAGCTACTTAGCTTGGTACCAACAGAGACCTGGACAATCTCCTAGGCTGCTCATCTACTGGGCATCCACCCGAGAATCGGGGGTTCCTGATCGCTTCAGCGGCAGTGGGTCCACAACAGATTTCGCTCTTACCATCAGCAGCTTCCAGCCTGAAGACGCGGCAGTGTATTACTGCCAGCAGGGTTATAGTTTTCCATATAGTTTCGGCAGTGGGACCAGGCTGGAAATCAGA >48B8_VK (SEQ ID NO: 167)GATGTTGTGATGACTCAGTCTCCCAGCTCCGTGACTGCATCTGTAGGAGAGAAGGTCACTATCAACTGTAAGTCCAGCCAGAGTGTGTTATACACCTCCAACCACAAAAACTACTTAGCTTGGTACCAGCAGAGACTTGGACAGTCTCCTAGGCTGCTCATCTACTGGGCATCCACCCGAGAATCGGGGGTTCCTGATCGATTCAGCGGCAGTGGGTCCACAACAGATTTCACTCTGACCATCAGCAGCTTCCAGCCTGAAGACGCGGCAGTGTATTACTGCCAGCAGGGATGGAGTTTTCCATATAGTTTCGGCAGTGGGACCAGGCTGGAAATCAAA >48D2_VK (SEQ ID NO: 168)GATATTGTGATGACCCAGACTCCCAGCTCCGTGACTGCGTCTGCAGGAGAGAAGGTCACCATCAATTGTAAGTCCAGCCAGAGTGTATTATACAACTCCAACCAGAAAAACTACTTAGCTTGGTACCAGCAGAGACTTGGACAGTCTCCTAGGCTGCTCATCTACTGGGCATCCACCCGAGAATCGGGGGTTCCTGATCGATTCAGCGGCAGTGGGTCCACAACAGATTTCACTCTGACCATCAGCAGCTTCCAGCCTGAAGACGCGGCAGTGTATTACTGCCAGCAGGGATGGAGTTTTCCATATACTTTCGGCAGTGGGACCAGGCTGGAAATCAAA >48B6_VK (SEQ ID NO: 169)GATATCCAGTTGACCCAGTCTCCCAGCTCCGTGACAGCGTCTGCAGGAGAGAAGGTCACCATCAATTGTAAGTCCAGCCAGAGTGTGTTATACGGCTCCAACCAGAAAAACTACTTAGCTTGGTACCAGCAGAGACTTGGACAGTCTCCTAGGCTGCTCATCTACTGGGCATCCACCCGAGAATCGGGGGTTCCTGATCGATTCAGCGGCAGTGGGTCCACAACAGATTTCACTCTGACCATCAGCAGCTTCCAGCCTGAAGACGCGGCAGTGTATTACTGCCAGCAGGGATGGAGTTTTCCATATACTTTCGGCAGTGGGACCAGGCTGGAAATCAAA >48C8_VK (SEQ ID NO: 170)GACATCCAGTTGACCCAGTCTCCCAGCTCCGTGACTGTGTCTGTAGGAGAGAAGGTCACCATCAATTGTAAGTCCAGCCAGAGTGTATTATACAACTCCAACCAGAAAAACTACTTAGCTTGGTACCAGCAGAGACTTGGACAGTCTCCTAGGCTGCTCATCTACTGGGCATCCACCCGAGAATCGGGGGTTCCTGATCGATTCAGCGGCAGTGGGTCCACAACAGATTTCACTCTGACCATCAGCAGCTTCCAGCCTGAAGACGCGGCAGTGTATTACTGCCAGCAGGGATGGAGTTTTCCATATACTTTCGGCAGTGGGACCAGGCTGGAAATCAAA >48E5_VK (SEQ ID NO: 171)GACATCCAGATGACCCAGTCTCCCAGCTCCGTGACTGCGTCTGCAGGAGAGAAGGTCACCATCAATTGTAAGTCCAGCCAGAGTGTATTATACAACTCCAACCAGAAAAACTACTTAGCTTGGTACCAGCAGAGACTTGGACAGTCTCCTAGGCTGCTCATCTACTGGGCATCCACCCGAGAATCGGGGGTTCCTGATCGATTCAGCGGCAGTGGGTCCACAACAGATTTCACTCTGACCATCAGCAGCTTCCAGCCTGAAGACGCGGCAGTGTATTACTGCCAGCAGGGATGGAGTTTTCCATATACTTTCGGCAGTGGGACCAGGCTGGAAATCAAA >48D7_VK (SEQ ID NO: 172)GATATTGTGATGACCCAGACTCCCGCCTCCGTGACTGCGTCTGCAGGAGAGAAGGTCACCATCAATTGTAAGTCCAGCCAGAGTGTGTTATTCAGCTCCAACCAGAAAAACTACTTAGCTTGGTACCAGCAGAGAGTTGGACAGTCTCCTAGGCTGCTCATCTACTGGGCATCCACCCGAGAATCGGGGGTTCCTGATCGATTCAGCGGCAGTGGGTCCACAACAGATTTCACTCTTACCATCAGCAACTTCCAGCCTGAAGACGCGGCAGTGTATTACTGCCAGCAGGGTTATAGTTTTCCATATAGTTTCGGCAGTGGGACTAGGCTGGAAATCAGA >48E2_VK (SEQ ID NO: 173)GATGTTGTGATGACTCAGTCTCCCAGCTCCGTGACTGCGTCTGCAGGAGAGAAGGTCACCATCAATTGTAAGTCCAGTCAGAGTGTGTTATGGAGCTCCAACCAGAAAAACTACTTAGCTTGGTACCAGCAGAGAGTTGGACAGTCTCCTAGGCTGCTCATCTACTGGGCATCCACCCGAGAATCGGGGGTTCCTGATCGATTCAGCGGCAGTGGGTCCACAACAGATTTCACTCTTACCATCAGCAACTTCCAGCCTGAAGACGCGGCAGTGTATTACTGCCAGCAGGGTTATAGTTTTCCATATAGTTTCGGCAGTGGGACCAGGCTGGAAATCAGA >49A1_VL (SEQ ID NO: 174)CAGTCTGTGTTGACGCAGCCTCCCTCCGTGTCTGGGTCTCCAGGAAAGACGGTCACCATCTCCTGTGCAGGAACCAGCAGTGATGTTGGGTATGGAAACTATGTCTCCTGGTACCAGCAGCTCCCAGGCACGGCCCCCAAACTCCTGATCTTTGCAGTCAGCTATCGAGCCTCAGGGATCCCTGATCGCTTCTCTGGCTCCAAGTCAGGCAACACGGCCTTTTTGACCATCTCTGGGCTCCAGTCCGAGGACGAGGCTGATTATTACTGTGCCTCATATAGAAGCAGCAACAATGCTGCTGTGTTCGGCGGAGGGACCCATCTGACCGTCCTG >49D2_VL (SEQ ID NO: 175)GCACAGTCTGTGCTGACGCAGCCTCCCTCCGTGTCCGGAACTCTGGGCAAGACGCTCACCATCTCCTGCGCTGGAACCAGCACTGATGTTGGATACGGAAACTATGTCTCCTGGTACCAACAGCTCCCAGGCACGGCCCCCAAACTCCTGATCTTTGCAGTCAGCTATCGAGCCTCAGGGATCCCTGATCGCTTCTCTGGCTCCAAGTCAGGCAACACGGCCTTTTTGACCATCTCTGGGCTCCAGTCCGAGGACGAGGCTGATTATTACTGTGCCTCATATAGAAGCAGCAACAATGCTGCTGTGTTCGGCGGAGGGACCCATCTGACCGTCCTG >49G3_VL (SEQ ID NO: 176)CAGTCTGCCCTGACTCAGCCTCCCTCCGTGTCCGGAACTCTGGGCAAGACGCTCACCATCTCCTGCGCTGGAACCAGCACTGATGTTGGATACGGAAACTATGTCTCCTGGTACCAACAGCTCCCAGGCACGGCCCCCAAACTCCTGATCTTTGCAGTCAGCTATCGAGCCTCAGGGATCCCTGATCGCTTCTCTGGCTCCAAGTCAGGCAACACGGCCTTTTTGACCATCTCTGGGCTCCAGTCCGAGGACGAGGCTGATTATTACTGTGCCTCATATAGAAGCAGCAACAATGCTGCTGTGTTCGGCGGAGGGACCCATCTGACCGTCCTG >49D3_VL (SEQ ID NO: 177)CTGCCTGTGCTGACTCAGCCTCCCTCCGTGTCCGGAACTCTGGGAAAGACGCTCACCATCTCCTGCGCTGGAACCAGCAGTGATGTTGGATACGGAAACTATGTCTCCTGGTACCAACAGCTCCCAGGCACGGCCCCCAAACTCCTGATCTATGCAGTCAGCTATCGAGCCTCAGGGATCCCTGATCGCTTCTCTGGCTCCAAGTCAGGCAACACGGCCTCCCTGAGCATCTCTGGGCTCCAGTCTGAGGACGAGGCTGATTATTACTGTGCCTCATATAGAAGCAGCAACAAAAATGCTGTGTTCGGCGGAGGGACCCATCTGACCGTCCTG >49A11_VL (SEQ ID NO: 178)CAGTCTGCCCTGACTCAGCCTCCCTCCGTGTCTGGGTCTCCAGGAAAGACGGTCACCATCTCCTGTGCAGGAACCAGCAGTGATGTTGGATACGGAAACTATGTCTCCTGGTACCAAAAGCTCCCAGGCACAGCCCCCAAACTCCTGATCTATGCAGTCAGCTATCGAGCCTCAGGGATCCCTGATCGCTTCTCTGGCTCCCGGTCAGGCAACACGGCCTCCCTGACCATCTCTGGGCTCCAGTCTGAGGACGAGGCTGATTATTACTGTGCCTCATATAGAATCACCAACAGGCACAGCGTGTTCGGCGGAGGGACCCATCTGACCGTCCTG >49C4_VL (SEQ ID NO: 179)CAGTCTGCCCTGACTCAGCCTCCCTCCGTGTCTGGAACTCTGGGAAAGACGGTCACCATCTCCTGCGCTGGAACCAGCAGTGATGTTGGGTATGGAAACTATGTCTCCTGGTACCAAAAGCTCCCAGGCACAGCCCCCAAACTCCTGATCTATGCAGTCACCTATCGAGCCTCAGGGATCCCTGATCGCTTCTCTGGCTCCAAGTCGGGCAACACGGCCTCCCTGACCATCTCTGGGCTCCAGTCTGAGGACGAGGCTGATTATTACTGTGCCTCATATAGAAGAAGTACTAATGTGGGGGTGTTCGGCGGAGGGACCCATCTGACCGTCCTG >49E11_VL (SEQ ID NO: 180)CAGGCTGTGCTGACTCAGCCTCCCTCCGTGTCCGGAACTCTGGGAAAGACGGTCACCATCTCCTGCGCTGGAACCAGCAGTGATGTTGGATACGGAAACTATGTCTCCTGGTACCAAAAGCTCCCAGGCACAGCCCCCAAACTCCTGATCTATGCAGTCAGCTATCGAGCCTCAGGGATCCCTGATCGCTTCTCTGGCTCCAAGTCAGGCAACACGGCCTCCCTGACCATCTCTGGGCTCCAGTCTGAGGACGAGGCTGATTATCACTGTGCCTCATATAGAACCAGCAACAATGTGGCTGTGTTCGGCGGAGGGACCAAGCTGACCGTCCTC

Example 3: Epitope Mapping

Different ectodomains of c-Met (Decoy, SEMA, SEMA-PSI, SEMA-PSI-IPT1-2and IPT3-4, (C. Basilico, et al., J Biol. Chem. 283:21267-2127, 2008)were immobilized (1 μg/ml) on a maxisorb plate in PBS over night at 4°C. The antibodies (mAbs) were added in three-fold dilutions startingwith 1 μg/ml and allowed to bind for 1 h at room temperature. Bindingwas revealed with HRP-conjugated Protein A and TMB and read at 450 nmafter stopping the reaction with H₂SO₄.

Based on the binding results, the mAbs could be mapped to differentdomains of c-Met, except for several mAbs that only bound to Decoy c-Metand not to any of the other domains tested (Table 8). Some antibodiesbinding only the Decoy c-Met may bind to the IPT 2-3 region or to aconformational epitope not seen on the recombinant c-Met proteinfragments. An example of antibody 40B8 binding to the IPT1-2 domain isshown in FIG. 4A and 36C4 binding to the SEMA domain in FIG. 4B.

TABLE 8 c-Met domain recognition for antagonistic mAbs and off-rates ofthe corresponding Fabs mAb Domain recognition k_(off) (10⁻⁴ s⁻¹) 12G4IPT1-2 1.3 13E6 Decoy 6.5 20F1 SEMA 69 20A11 Decoy 9 38H10 IPT1-2 1236C4 SEMA 6.4 40B8 IPT1-2 13 34H7 SEMA 16

Example 4: Scatter Assay

Serum starved Human Pancreatic cancer cells (HPAF) cells were plated in96-well plates, 7000 cells/well. At day 2, antibodies were added intriplicate at concentrations of 30, 10, 3 and 1 μg/ml and incubated withthe cells for 30 minutes before 1.25 ng/ml HGF/well was added. The HPAFcells were also incubated with the antibodies in the absence of HGF. Atday 3, the cells were fixed and stained with crystal violet. Scoring ofthe amount of scattering was done three times independently and by twodifferent persons.

The results showed a dose-dependent inhibition of HGF-induced scatteringby the mAbs, with strong blocking for eight antibodies of the 13 tested,of which five (12G4, 20A11, 38H10, 36C4 and 40B8) showed completeblocking of the scattering at 30 μg/ml. All eight antagonistic mAbs(12G4, 13E6, 20F1, 20A11, 38H10, 34H7, 36C4 and 40B8) were also devoidof agonistic effects at 30 μg/ml in the absence of HGF. FIG. 5 shows anexample of the scattering results of 38H10 in the presence and absenceof HGF as compared to the medium control and the HGF control.

Example 5: Cross Reactivity to Rhesus and Mouse c-Met

Cross reactivity to Rhesus (Maccaca mulatta, US20090191580_5) c-Met ECDand mouse c-Met (R&D systems cat no: 527-ME) was performed in a bindingELISA. Rhesus ECD was immobilized in PBS (1 μg/ml) on a 96-well maxisorbplate and incubated at 4° C. over night. After blocking with 1% caseinin PBS, the antibodies in dilutions starting with 10 μg/ml were addedand allowed to bind for 1 h at room temperature. The plate was washedand a goat anti-human Fcγ antibody (Jackson) was added and incubated for1 h at room temperature. After washing, TMB was added and the plate readat 620 nm.

Since the mouse c-Met also contained a Fc portion, the mAbs (2 μg/ml)were immobilized on a 96 well maxisorb plate over night at 4° C. and,after blocking, 100 ng/ml of the mouse c-Met was added and incubated for1 h at room temperature. A HRP-conjugated mouse anti-His antibody(Serotech) was added and incubated for 1 h at room temperature. Afterwashing, TMB was added and the plate read at 620 nm. A biotinylated goatanti-mouse c-Met antibody revealed with strep-HRP was used as a positivecontrol for the mouse c-Met.

No significant binding (>10-fold) to mouse c-Met was observed for any ofthe mAbs.

All six mAbs tested showed cross-reactivity to Rhesus c-Met ECD with analmost identical binding compared to that on the human ECD c-Met (Decoy)(Table 9).

TABLE 9 EC50 (nM) of mAbs binding to Rhesus or human c-Met (Decoy) mAbRhesus Human 38H10 0.17 0.19 40B8 0.13 0.14 36C4 0.14 0.13 20A11 3.4 4.313E6 0.19 0.19 12G4 0.34 0.42

Example 6: Competition with HGF for Binding to c-Met

Competition with N-terminally biotinylated HGF for binding toimmobilized c-Met was performed using an ELISA-based competition assay.Five μg/ml mouse anti-His antibodies (Serotech) was immobilized on amaxisorb plate and, after blocking with 1% casein in PBS for 2 h, 100ng/ml recombinant dimeric c-Met was added and incubated for 1 h at roomtemperature. After washing, dilutions of the antibodies were added andallowed to bind to the captured c-Met for 30 minutes, before 25 ng/mlN-terminally biotinylated HGF (R&D systems, 294-HGN/CF) was added.Biotinylated HGF was incubated at room temperature for 1 h beforewashing. Horseradish-conjugated streptavidin (strep-HRP) was added andincubated for an additional hour. TMB was added and the plate read at620 nm. An isotype control (hIgG1λ) was included as a control as well asmurine 5D5 antibody. Competition was expressed as percentage competitionas compared to the controls (strep-HRP only or hIgG1λ) and plottedagainst the concentration of antibodies. An IC₅₀ was calculated usingGraphPad Prism (Table 10). Antibodies 13E6 and 20A11 only displaced HGFpartially (about 50%), which may be related to the epitope these twomAbs recognize on the c-Met. FIG. 6 shows an example of anti-c-Metantibodies competing with HGF for c-Met binding.

TABLE 10 IC₅₀ of mAbs competing with HGF for c-Met binding mAbs IC₅₀(nM) 12G4 0.26 13E6 partial 20F1 0.36

Example 7: Agonistic and Antagonistic Properties of mAbs Measured in theProliferation Assay Using HGF-Dependent Pancreatic BxPC3 Cells

Human pancreatic BxPC3 cells (ATCC cat no. CRL-1687) respond to HGF andwere used for the proliferation assay to investigate the eight candidatemAbs further. In brief, 15,000 cells were seeded in the presence ofserum and then serum starved over night following attachment (4-6 hoursafter seeding). The mAbs were added in doses from 20 ng/ml to 40 μg/mlin the presence or absence of 75 ng/ml HGF in order to test antagonismand agonism respectively. After three days incubation, Alamar blue wasadded to the cells and incubated at 37° C. for 4 hours before readingfluorescence at excitation 550 nm and emission 590 nm, thereby yieldinga read-out on cell proliferation. The assay was repeated three times. Anexample of one independently performed experiment for agonism (FIG. 7A)and one for antagonism (FIG. 7B) is shown for the candidate mAbs andbenchmark mAbs, including chimeric 224G11 (c224G11, Pierre Fabre).Proliferation is expressed as a percentage of the proliferation obtainedwith 75 ng/ml HGF. Three of the mAbs (38H10, 40B8 and 36C4) show lessthan 20% induced proliferation, with 38H10 in the same range as thebenchmark c224G11.

Example 8: VL Shuffling for Improved Affinity

VL chain shuffling was used to improve the affinity of the two mAbs,38H10 and 48A2. In this method, the heavy chain of the parental clone(VHCH1 of 36C4 or 38H10) was reintroduced in the phagemid-light chainlibrary (see Example 1). The heavy chain was extracted from anexpression vector, which lacks the bacteriophage-derived gene 3necessary for display, to further avoid contamination of the parentallight chain in the selection procedure. The heavy chain was cloned intothe phagemid-light chain library and the ligated DNA was electroporatedinto E. coli TG1 cells to create the light chain shuffled library. Thesize of libraries was above 10⁸ clones.

Affinity selections, combined with off-rate washes, were performed toselect for chain shuffled Fabs with an improved affinity for c-Met. Aset-up was chosen where different amounts of Fab-expressing phages wereincubated with different concentrations of Fc-Met in solution (see Table11). By adding the c-Met in excess over the phage, but in aconcentration lower than the desired affinity constant, the binding ofthe higher affinity phage was favored. The Fc-Met:phage complexes werethen captured on a microtiterplate coated with an anti-Fc mAb. The platewas washed with decoy cMein solution at 37° C. to prevent the rebindingof dissociated phages to the captured Fc-Met. Each round the time ofwashing was increased (see Table 11) to select for phages with a betteroff-rate by washing away the lower affinity variants. Phages were elutedwith trypsin and used for infection of E. coli TG1 cells. In total, 5rounds of selection were done. In addition the amount of input phage wasdecreased in subsequent rounds to reduce background on the one hand andon the other hand to lower the mAb concentration thereby increasing thestringency of the selection.

Screenings of at least 30 clones from selection rounds III, IV and Vwere performed. The clones were grown in deep well plates (1 mlexpressions) and periplasmic fractions were prepared. These periplasmicextracts were first tested for competition with HGF in an ELISA (seeExample 2). For 38H10 the frequency of competing clones that gave lowELISA signals increased in subsequent selection rounds, with clearenrichment of the competitors in the different rounds.

The clones were then tested for their dissociation constants by SurfacePlasmon Resonance. Around 3000 RU of Fc-Met was immobilized directlyonto a CMS chip to obtain a clear binding profile from the periplasmicextracts. Clones with an improved off-rate were sent for sequencing.

Originally paired light chains (both Vkappa for 38H10 and Vlambda for36C4) were obtained after light chain shuffling, but an improvedoff-rate over the parental Fab was only found for 38H10 variant 48A2(10-fold by Surface Plasmon Resonance). For 36C4 no improvement inaffinity was obtained so the parental mAb was retained for further work.

TABLE 11 Parameter variation for each round of selection for VLshuffling. RI RII RIII RIV RV Concentrations 24 nM 2.4 nM 240 pM 24 pM24 pM Fc-Met 2.4 nM 0.24 nM 24 pM 2.4 pM 2.4 pM 0.24 nM 0.024 nM 2.4 pM0.24 pM 0.24 pM Vol. Phage 10 μl 1 μl 0.1 μl 0.1 μl/ 0.1 μl/ 0.01 μl0.01 μl Time of washing 0 h 2 h O/N O/3N O/6N Conditions — 37° C., 1237° C., 1.2 37° C., 0.12 37° C., 0.12 nM Decoy Met nM Decoy Met nM DecoyMet nM Decoy Met in 1% casein in 1% casein in 1% casein in 1% casein

A number of VL shuffled Fabs sharing the 38H10 heavy chain variabledomain (SEQ ID NO: 49). The shuffled light chains are listed below(amino acid and nucleotide sequences are listed in Tables 6 and 7)together with the off-rates for the corresponding Fabs (each Fabincludes 38H10 as the heavy chain) (Table 19).

TABLE 19 VL shuffled Fab k_(off) (10⁻⁴ s⁻¹) 48A1 8.1 48A11 2.5 48B8 3.348D2 1.3 48B6 1.2 48A2 2.3 48C8 3.3 48E2 2.9 48E5 1.9 48D7 2.5 38H10 5.0

A number of VL shuffled Fabs sharing the 36C4Q heavy chain variabledomain (SEQ ID NO: 88). The shuffled light chains are listed below(amino acid and nucleotide sequences are listed in Tables 6 and 7)together with the off-rates for the corresponding Fabs (each Fabincludes 36C4Q as the heavy chain) (Table 20).

TABLE 20 VL shuffled Fab k_(off) (10⁻⁴ s⁻¹) 49A1 1.7 49D2 1.7 49G3 1.949D3 8.2 49A11 4.8 49C4 1.8 49E11 6.3 36C4Q 1.7

Example 9: Agonistic and Antagonistic Properties of mAbs Measured in thePhosphorylation Assay Using HGF-Dependent NSCLC A549 Cells

In order to further investigate the mAbs a phosphorylation assay was setup using HGF-dependent NSCLC A549 cells (ATCC no. CCL-185). The cellswere incubated both in the absence of HGF in order to assess agonisticactivity of each antibody as well as in the presence of HGF in order toassess antagonistic potency of each antibody. In brief, 40,000 cellswere plated and serum starved overnight after attachment to the plate(4-6 h after seeding). The cells were then treated for 15 minutes at 37°C. with mAbs. For the antagonism assay 100 ng/ml HGF was added andincubated for another 15 minutes at 37° C. HGF alone (100 ng/ml) wasalso tested to provide reference values for the experiment. The cellswere washed with cold PBS and lysed with mild lysis buffer containingPMSF (Cell signalling #9803 including 1 mM PMSF, Sigma Aldrich) for 15minutes on ice. 50 μl of the lysate was added per well in a 96-wellplate pre-coated with goat anti-c-Met antibody and blocked with 1%casein-PBS. The c-Met in the lysate was then allowed to bind overnightat 4° C. Phospho-c-Met was revealed with a rabbit anti-pY1234/1235antibody (Cell signaling) and a HRP-conjugated goat anti-rabbit antibody(Jackson Laboratories). TMB was added and the reaction stopped with 1MH₂SO₄ and read at 450 nm.

The antibodies were tested in duplicate at different concentrations, andthe control mAbs U16 (irrelevant mAb, negative control), chimeric 224G11(c224G11, Pierre Fabre) and murine 224G11 (mPF, Pierre Fabre) wereincluded in each run alongside HGF only and cells only as positive andnegative controls. FIG. 8A-B shows the low agonistic effects of threemAbs as compared to the controls. Compared to the benchmark c224G11, theantibodies 38H10, 48A2 and 36C4 (not shown) all give lower levels ofphosphorylated c-Met. FIG. 9 shows the potency of mAbs 48A2, 36C4 and40B8 in blocking HGF-induced phosphorylation compared to the benchmarkc224G11, with 36C4 having the best blocking potency. The percentagephosphorylation is expressed as the percentage of maximumphosphorylation induced by 100 ng/ml HGF.

Phosphorylation assays using BxPC3 cells were done in the same way asfor A549 cells and the results correlated very well to those obtainedwith the A549 cells (data not shown).

Example 10: Inhibitory Effect of Anti-cMet Antibodies on cMetAutophosphorylation MKN-45 Cells

To examine the capability of the mAbs to inhibit phosphorylation inconstitutively activated cells we used gastric MKN-45 cells (DMSZ catno. ACC 409). These cells have a c-Met gene amplification resulting inover-expression of c-Met and thereby constitutive phosphorylation, i.e.independent of HGF.

Briefly, 5,000 cells were seeded in the presence of serum and incubatedfor 24 h with different concentrations of the mAbs at 37° C. An ELISAwas performed for quantification of phosphorylated c-Met as described inExample 8.

In FIG. 10 the blocking effect of the mAbs on cMet phosphorylation inMKN-45 cells can be seen (% inhibition). The response was normalizedagainst the negative control mAb U16.1 (0% inhibition). It can beconcluded that SIMPLE™ antibody 36C4 is the most potent inhibitor ofHGF-independent phosphorylation in MKN-45 cells. c224G11 was not aspotent as 36C4 and 48A2. 40B8 only blocks around 40% at the highestconcentration and levels off rapidly.

Example 11: Antibody Induced ADCC in MKN-45 Cells

200,000 MKN-45 cells were seeded the day before addition of theantibody. Dilutions of antibodies were added to the cells andpre-incubated 60 minutes before effector cells (whole blood-derivedPBMCs from one donor, incubated over night before addition to the targetcells) were added at an E:T ratio (natural killer cells (NK):target cellline) of 5:1. The NK cell subpopulation in PBMCs was determined by flowcytometry for every donor as the ratio of anti-CD16 to anti-CD56. After4 hrs incubation the plates were read using the Dead-Cell Protease Kit(CytoTox-Glo™ Cytotoxicity Assay from Promega (CAT # G9291)) to give thepercentage of lysed cells.

FIG. 11 shows the specific lysis induced by three mAbs, 48A2, 40B8 and36C4, tested in a dose response compared with c224G11. The EC50 of thethree tested mAbs is in the same in the same range as c224G11 (4.3, 4.6,5.0, for 48A2, 40B8 and 36C4 and 2.8 ng/ml for c224G11).

Example 12: Potelligent™ 36C4 Induced ADCC in NCI-H441 Cells

Defucosylated 36C4 was produced in the Potelligent™ CHO cells (Biowa)and purified with Protein A. Human peripheral blood mononuclear cells(PBMC) from 3 donors were separately purified from heparinized wholeblood by standard ficoll separation and were used as effector cells. Thecells were suspended at 2×10⁶/ml in media containing 200 U/ml of humanIL-2 and incubated over night at 37° C. The following day, adherent andnon-adherent cells were collected and washed once in culture media.

Target to effector ratios of 1:50 were used. The cells were suspended at5×10⁶ cells/ml and 100 μl added per well.

10⁶ target cells NCI-H441, were incubated with 100 μCi ⁵¹Cr in 0.5 mlFCS for 60 minutes in a water bath at 37° C. The cells were washed,resuspended in 1 ml FCS and incubated for 30 minutes in a water bath at37° C. Then the cells were washed twice with medium and brought to afinal volume of 2×10⁵ cells/ml and 50 μl was added per well.

The assay was carried out in triplicate. 50 μl of the labelled cellswere incubated with 100 μl of effector cells and 50 μl of antibody. Onerow of a 96-well plate contained only target cells in order to controlfor spontaneous release of ⁵¹Cr. On another 96-well plate, one row ofwells contained only target cells treated with 1% Triton-X (in order tocompletely lyse the cells) giving a read-out for maximum release of⁵¹Cr. After 4 hours incubation at 37° C., 50 μl of supernatant wascollected, transferred to a Lumaplate-96, dried and counted in a betacounter.

The percent lysis was determined by the equation: % Lysis=(sampleCPM−spontaneous release CPM)/(maximum release CPM−spontaneous releaseCPM)×100. FIG. 12 shows the percentage lysis of the NCI-H441 cells byPotelligent 36C4 (ADCC-enhanced by defucosylation) versus normalfucosylated 36C4. Defucosylated 36C4 (Potelligent 36C4) inducesexcellent lysis of NCI-H441 cells with an IC50 of 0.13 ng/ml, whereasnormal fucosylated 36C4 does not induce any lysis of the NCI-H441 cells.The percentage lysis induced by c224G11 was very low. Clearlydefucosylation of 36C4 dramatically enhances its capacity to induce ADCCof NCI-H441 cells.

Example 13: In Vitro Effect of ADCC-Enhanced 36C4 on NCI-H441 Cells

Non-fucosylated mAbs by the Potelligent™ technology has no significanteffect in vivo in mice. However, Fc mutations (S239D, I332E) have beenshown to have an effect in vivo, enhancing the ADCC effect of mAbs byincreasing the affinity to the mouse FcγRIII, CD16 (Lazar G A et al,PNAS, 103. 2006).

The S239D, I332E mutations were inserted into the IgG1 of 36C4 usingsite-directed mutagenesis with specific primers, generating 36C4E. 36C4Ewas produced in the same way as the parental 36C4 using HEK293E cellsand purified using Protein A. There was no difference in productionlevels or the level of HGF displacement in an ELISA based competitionassay after the mutations as compared to the parental 36C4. The ADCCeffect was investigated in the ⁵¹CR release assay on NCI-H441 cells (asdescribed in Example 12). There was no effect of the 36C4 and thePotelligent 36C4 showed a slightly lower percentage lysis than theADCC-enhanced Fc mutant 36C4E. The EC₅₀ for 36C4-POT vs 36C4E was 0.04μg/ml versus 0.26 μg/ml.

Example 14: In Vivo Effect of ADCC-Enhanced 36C4 on MKN-45 Xenografts

6-8 week old CD-1 nude mice were injected subcutaneously with 3 millionMKN-45 cells. The tumors were measurable after 8 days post injectionsand the treatment was started on day 9 with intraperitoneal injectionstwice per week with different amounts of test antibody. Groups of sixmice were injected with 36C4E (30, 10, 3 and 1 mg/kg) and the volume ofthe tumors were measured (at the time injections were performed). AnIgG1 isotype control (Synagis®) was included as a control as well asc224G11, both at the highest concentration 30 mg/kg.

At day 23 after the injection of the cells (15 days after the start ofthe treatment) a dose-dependent effect on the tumor volume could beobserved in the mice treated with the 36C4-E. c224G11 had no effect onthe tumor growth as compared to the isotype control (FIG. 13).

Example 15: Human-Llama glama Chimeric c-Met Fusion Proteins

Human-Llama glama chimeric c-Met ECD fusion proteins were constructed byexchanging the IPT domain of human and Llama glama c-Met in order to mapthe domain recognition of the mAbs. The construction was done usingstandard recombinant DNA and PCR methodologies. The Llama glama andhuman c-Met were amplified from RNA converted to cDNA from peripheralblood lymphocytes (PBLs) from two donors of each species. The llama andhuman c-Met ECD (aa 25-932) were cloned into a eukaryote expressionvector with a His tag for expression as soluble proteins by HEK293cells. The IPT1-4 (aa 568-932) from llama was exchanged with the humanIPT1-4 in the human c-Met and conversely the human IPT1-4 was exchangedwith the llama IPT1-4 in the llama c-Met using splicing and overlapextension PCR. All four constructs, llama c-Met, llama/human-IPT, humanc-Met, human/llama-IPT were expressed in HEK293 cells and purified usingIMAC columns. FIG. 15 shows the alignment (88% identity) of human c-Met(Genbank X54559) with the Llama glama c-Met amplified from PBLs from twodonors.

Example 16: Domain Mapping of mAbs Using Chimeric c-Met ECD

200 ng of the different chimeric recombinant cMet proteins wereimmobilized on maxisorb plates overnight at 4° C. After washing withPBS, the plates were blocked with 0.1% casein for 2 h at RT, before themAbs were added and allowed to bind to the c-Met for 1 h at RT. Afterwashing, HRP-conjugated goat anti-human antibody (diluted 1/5000,Jackson Labs) was added and incubated for 1 h at RT before additionalwashing and addition of TMB. The optical density at 620 nm was read andthe values were represented in a graph against the concentration ofmAbs.

FIG. 16A shows binding of the 36C4 to the human c-Met (WT) and thehuman/llama IPT1-4 thus indicating binding to the SEMA-PSI region. FIG.16B shows binding of mAb 13E6 to the human c-Met and to the llama/humanIPT1-4. No binding was observed to the llama c-Met for any of the mAbs.48A2 was also tested but mainly showed binding to the construct with thehuman SEMA-PSI and some binding to the construct with the human IPT,indicating that there was binding to an overlapping region in thePSI-IPT domains.

Example 17: Binding of 36C4 and 48A2 to Non-Overlapping Epitopes onc-Met Using Surface Plasmon Resonance

To investigate if the two mAbs 36C4 and 48A2 bound to non-overlappingepitopes, 3000 RU of 36C4 or 48A2 were coupled to a CMS chip. 60 μl of40 μg/ml monomeric Decoy Met was injected to form a complex on the chip.60 μl of 10 μg/ml 36C4 was injected (FIG. 16A). As shown in FIG. 16A,binding is observed to the Met:48A2 complex only. Similarly binding of48A2 mAb to the Met:36C4 complex and Met:48A2 complex was performedusing 3000 RU of 36C4 or 48A2 coupled to a CMS chip. 60 μl 40 μg/mlDecoy Met was injected to perform a complex on the chip. Then 60 μl 10μg/ml 48A2 was injected. Binding was observed to the Met:36C4 complexonly as shown in FIG. 16B. These results indicate recognition ofnon-overlapping epitopes of mAbs 36C4 and 48A2.

Example 18: Increased Inhibitory Effect on c-Met AutophosphorylationUsing a Combination of Anti-cMet Antibodies

The two mAbs 36C4 and 48A2, recognizing non-overlapping epitopes onc-Met as shown by Biacore (FIG. 16), were combined at ratio 1:1 in aphopshorylation assay using the HGF-independent MKN-45 cells asdescribed in Example 10. The antibody mix was compared with 36C4 and48A2 over a range of concentrations for the ability to block c-Metautophosphorylation (note that total antibody concentrations of the mixare equal to total antibody concentration for the individual antibodies:i.e. for the 0.2 nM dose the mix is 0.1 nM of each of 36C4 and 48A2,whilst for the pure mAb this would contain 0.2 nM 36C4 or 48A2). Thecombination showed significantly better inhibition of cMetautophosphorylation compared with the individual mAbs. At 0.78 nM mAb,the mix shows 75% inhibition of phosphorylation compared to 42% and 32%for 36C4 and 48A2 alone (FIG. 17). The combination of 36C4 and 48A2 wasalso more potent than the individual antibodies at blockingautophosphorylation of the NSCLC EBC-1 cells (data not shown).

Example 19: Combination of Non-Overlapping mAbs Show Lower Levels ofAgonism and Better Blocking Potency in a Phosphorylation Assay UsingNSCLC A549 Cells

A phosphorylation assay using NSCLC A549 cells was run as in Example 9to investigate the mAbs 36C4 and 48A2 either in combination (ratio 1:1)or individually for their agonistic activity and antagonistic activity(in the absence or presence of HGF respectively). The level of agonismwas lower for the combination (36C4 and 48A2) than for either of themAbs alone (FIG. 18A) and the effect of blocking HGF-inducedphosphorylation was significantly increased for the combination (36C4and 48A2) compared to either mAb alone (FIG. 18B).

Example 20: Inhibition of Tumor Growth in a U87-MG Xenograft Model

To investigate the inhibitory effect of 36C4 mAb on tumor growth invivo, 3×10⁶ U87-MG cells with autocrine HGF (ATCC HTB-14) were injectedsubcutaneously in the right hind flank of Nude CD1 nu/nu mice. When thetumor reached 70-120 mm³ (day 19), the mice were stratified and begantreatment with 30 mg/kg intraperitoneal (i.p.) 36C4, c224G11 or isotypecontrol antibody twice per week. The treatment continued until day 35post-injection of the tumour cells, when the experiment was terminated.The tumor size was measured periodically during the experiment when mAbswere administered and the results are presented in FIG. 19. 30 mg/kg of36C4 inhibits U87-MG tumor growth as well as the comparator mAb c224G11.

Example 21: Germlining of 36C4 and 48A2

The VH and VL sequences of 36C4 and 48A2 were blasted against humangermline VH and VL sequences and 36C4 was closest related to thegermline sequences of the IGHV4-30-4*01 (66/76 framework identity) andIGLV2-18*02 (61/69 framework identity). 48A2 was closest related to thegermline sequences of IGHV1-46*01 (66/76 framework identity) andIGKV4-1*01 (53/70 framework identity).

The germlining process was performed as described in WO 2010/001251 andby Baca et al. (J. Biol. Chem. (1997) 272: 10678-10684) and Tsurushitaet al. (J. Immunol. Methods (2004) 295: 9-19). It was a library/phagedisplay approach, in which the deviating FR residues for both the humanand the llama residues were incorporated. The germlined library ofVH36C4 or 48A2 and VL36C4 and 48A2 were created by PCR-based geneassembly using overlapping oligonucleotides with specific mutations oncertain positions (identified in Tables 3 and 4). The mutations weredegenerate in order to encode the human as well as the llama amino acid,this being to prevent complete loss of binding in case the wild typeresidue is critical for high affinity binding. The assembled genes werecloned into a phagemid vector with the human CH and CL and TG1 E. coliwere transformed generating libraries of a total size of 10⁹ clones.

Phage display, applying stringent selection conditions (3-5 rounds ofselections with decreasing the amount of antigen and phage andincreasing length of competitive washes with access of c-Met), was usedto select for functional Fabs (as described in Example 8). Individualclones were screened for off-rate and the best hits were sequenced todetermine the human sequence identity. Clones with >94% human identitywere produced by transient expression upon transfection of HEK293E cellsand if productions were >15 μg/ml, they were further characterized.

TABLE 12 Amino acid sequences of the heavy and light chainvariable domains of germlined variants of 36C4 >55A12-54E_VH (SEQ ID NO: 92)QVQLVESGPGLVKPSQTLSLTCTVSGGSISTNYYYWSWIRQSPGKGLEWIGVIAYEGSTDYSPSLKSRVTISRDTSKNQFSLKLSSVTAEDTAVYYCARDVRVIATGWATANALDAWGQGTLVTVSS >55A12-54E_VL (SEQ ID NO: 93)QSALTQPPSVSGSPGQSVTISCAGTSSDVGYGNYVSWYQQPPGTAPKLLIFAVSYRASGVPDRFSGSKSGNTASLTISGLQAEDEADYYCASYRSSNNAAVFGGGTKLTVL >53E2-54E_VH (SEQ ID NO: 94)QVQLQESGPGLVKPSQTLSLTCAVSGGSISTNYYYWSWIRQHPGKGLEWIGVIAYEGSTDYSPSLKSRVTISVDTSKNQFSLQLSSVTPEDTAVYYCARDVRVIATGWATANALDAWGQGTLVTVSS >53E2-54E_VL (SEQ ID NO: 95)QSALTQPRSVSGSPGQSVTISCAGTSSDVGYGNYVSWYQQHPGTAPKLMIFAVSYRASGIPDRFSGSKSGNTAFLTISGLQAEDEADYYCASYRSSNNAAVFGGGTKLTVL >53E3_VH (SEQ ID NO: 96)QVQLQESGPGLVKPSQTLSLTCTVSGGSITTNYYYWSWIRQSPGKGLEWIGVIAYEGSTDYSPSLKSRVTISRDTSKNQFSLQLSSVTAEDTAVYYCARDVRVIATGWATANALDAWGQGTLVTVSS >53E3_VL (SEQ ID NO: 97)QSVLTQPPSVSGSPGQTVTISCAGTSSDVGYGNYVSWYQQLPGTAPKLMIFAVSYRASGIPDRFSGSKSGNTASLTISGLQSEDEADYYCASYRSSNNAAVFGGGTKLTVL >53A11_VH (SEQ ID NO: 98)QVQLQESGPGLVKPSQTLSLTCTVSGGSITTNYYYWSWIRQSPGKGLEWIGVIAYDASTDYSPSLKSRVTISRDTSKNQFSLQLSSVTAEDTAVYYCARDVRVIATGWATANALDAWGQGTLVTVSS >53A11_VL (SEQ ID NO: 99)QSVLTQPPSVSGSPGQTVTISCAGTSSDVGYGNYVSWYQQPPGTAPKLMIFAVSYRASGIPDRFSGSKSGNTAFLTISGLQSEDEADYYCASYRSSNNAA VFGGGTKLTVL

TABLE 13 Nucleotide sequences encoding heavyand light chain variable domains ofgermlined variants of 36C4 >55A12-54E_VH (SEQ ID NO: 100)CAGGTGCAGCTCGTGGAGTCGGGCCCAGGCCTGGTGAAGCCCTCGCAGACACTCTCCCTCACCTGCACAGTCTCTGGTGGCTCCATCAGCACCAACTATTACTACTGGAGCTGGATTCGCCAGTCGCCAGGGAAGGGGCTGGAGTGGATTGGAGTCATAGCTTATGAAGGCAGCACTGACTACAGCCCATCCCTCAAGAGCCGCGTGACCATCTCCAGGGACACGTCCAAAAACCAGTTCTCCCTGAAACTGAGCTCTGTGACCGCGGAGGACACGGCCGTGTATTACTGTGCCAGAGATGTAAGGGTAATCGCTACGGGTTGGGCTACTGCCAATGCTTTGGACGCATGGGGCCAGGGGACCCTGGTCACCGTGTCCTCA >55A12-54E_VL (SEQ ID NO: 101)CAGTCTGCGTTGACGCAGCCTCCTTCCGTGTCTGGGTCTCCAGGACAAAGCGTCACCATCTCCTGTGCAGGAACCAGCAGTGATGTTGGGTATGGAAACTATGTCTCCTGGTACCAGCAGCCGCCAGGCACGGCCCCCAAACTCCTGATCTTTGCAGTCAGCTATCGAGCCTCAGGGGTTCCTGATCGCTTCTCTGGCTCCAAGTCAGGCAACACGGCCTCTTTGACCATCTCTGGGCTCCAGGCTGAGGACGAGGCTGATTATTACTGTGCCTCATATAGAAGCAGCAACAATGCTGCTGTGTTCGGCGGAGGGACCAAACTGACCGTCCTA >53E2-54E_VH (SEQ ID NO: 102)CAGGTGCAGCTCCAGGAGTCGGGCCCAGGCCTGGTGAAGCCCTCGCAGACACTCTCCCTCACCTGCGCAGTCTCTGGTGGCTCCATCAGCACCAACTATTACTACTGGAGCTGGATTCGCCAGCATCCAGGGAAGGGGCTGGAGTGGATTGGAGTCATAGCTTATGAAGGCAGCACTGACTACAGCCCATCCCTCAAGAGCCGCGTGACCATCTCCGTGGACACGTCCAAGAACCAGTTCTCCCTGCAACTGAGCTCTGTGACCCCGGAGGACACGGCCGTGTATTACTGTGCCAGAGATGTAAGGGTAATCGCTACGGGTTGGGCTACTGCCAATGCTTTGGACGCATGGGGCCAGGGGACCCTGGTCACCGTGTCCTCA >53E2-54E_VL (SEQ ID NO: 103)CAGTCTGCGTTGACGCAGCCTCGTTCCGTGTCTGGGTCTCCAGGACAAAGCGTCACCATCTCCTGTGCAGGAACCAGCAGTGATGTTGGGTATGGAAACTATGTCTCCTGGTACCAGCAGCATCCAGGCACGGCCCCCAAACTCATGATCTTTGCAGTCAGCTATCGAGCCTCAGGGATTCCTGATCGCTTCTCTGGCTCCAAGTCAGGCAACACGGCCTTTTTGACCATCTCTGGGCTCCAGGCTGAGGACGAGGCTGATTATTACTGTGCCTCATATAGAAGCAGCAACAATGCTGCTGTGTTCGGCGGAGGGACCAAACTGACCGTCCTA >53E3_VH (SEQ ID NO: 104)CAGGTGCAGCTCCAGGAGTCGGGCCCAGGCCTGGTGAAGCCCTCGCAGACACTCTCCCTCACCTGCACAGTCTCTGGTGGCTCCATCACCACCAACTATTACTACTGGAGCTGGATTCGCCAGTCTCCAGGGAAGGGGCTGGAGTGGATTGGAGTCATAGCTTATGAAGGCAGCACTGACTACAGCCCATCCCTCAAGAGCCGCGTGACCATCTCCAGGGACACGTCCAAGAACCAGTTCTCCCTGCAACTGAGCTCTGTGACCGCGGAGGACACGGCCGTGTATTACTGTGCCAGAGATGTAAGGGTAATCGCTACGGGTTGGGCTACTGCCAATGCTTTGGACGCATGGGGCCAGGGGACCCTGGTCACCGTGTCCTCA >53E3_VL (SEQ ID NO: 105)CAGTCTGTGTTGACGCAGCCTCCTTCCGTGTCTGGGTCTCCAGGACAAACCGTCACCATCTCCTGTGCAGGAACCAGCAGTGATGTTGGGTATGGAAACTATGTCTCCTGGTACCAGCAGCTGCCAGGCACGGCCCCCAAACTCATGATCTTTGCAGTCAGCTATCGAGCCTCAGGGATTCCTGATCGCTTCTCTGGCTCCAAGTCAGGCAACACGGCCTCTTTGACCATCTCTGGGCTCCAGTCTGAGGACGAGGCTGATTATTACTGTGCCTCATATAGAAGCAGCAACAATGCTGCTGTGTTCGGCGGAGGGACCAAACTGACCGTCCTA >53A11_VH (SEQ ID NO: 106)CAGGTGCAGCTCCAGGAGTCGGGCCCAGGCCTGGTGAAGCCCTCGCAGACACTCTCCCTCACCTGCACAGTCTCTGGTGGCTCCATCACCACCAACTATTACTACTGGAGCTGGATTCGCCAGTCGCCAGGGAAGGGGCTGGAGTGGATTGGAGTCATAGCTTATGATGCGAGCACTGATTACAGCCCATCCCTCAAGAGCCGCGTGACCATCTCCAGGGACACGTCCAAGAACCAGTTCTCCCTGCAACTGAGCTCTGTGACCGCGGAGGACACGGCCGTGTATTACTGTGCCAGAGATGTAAGGGTAATCGCTACGGGTTGGGCTACTGCCAATGCTTTGGACGCATGGGGCCAGGGGACCCTGGTCACCGTGTCCTCA >53A11_VL (SEQ ID NO: 107)CAGTCTGTGTTGACGCAGCCTCCTTCCGTGTCTGGGTCTCCAGGACAAACCGTCACCATCTCCTGTGCAGGAACCAGCAGTGATGTTGGGTATGGAAACTATGTCTCCTGGTACCAGCAGCCGCCAGGCACGGCCCCCAAACTCATGATCTTTGCAGTCAGCTATCGAGCCTCAGGGATTCCTGATCGCTTCTCTGGCTCCAAGTCAGGCAACACGGCCTTTTTGACCATCTCTGGGCTCCAGTCTGAGGACGAGGCTGATTATTACTGTGCCTCATATAGAAGCAGCAACAATGCTGCTGTGTTCGGCGGAGGGACCAAACTGACCGTCCTA

TABLE 14 Amino acid sequences of the heavy and light chainvariable domains of germlined variants of 48A2 >56F3_VH (SEQ ID NO: 108)EVQLVQPGAEVKKPGASVKVSCKASGYIFTMNSIDWVRQAPGQGLEWMGRIDPEEGGTKYAQKFQGRVTMTADTSTSTAYMELSSLRSDDTAVYYCARVDDYYLGYDYWGQGTQVTVSS >56F3_VK (SEQ ID NO: 109)DIVMTQSPDSLAASLGERVTINCKSSQSVLFSSNQKNYLAWYQQRPGQSPKLLIYWASIRESGVPDRFSGSGSGTDFTLTISSLQAEDVAVYYCQQGYSFPYSFGSGTRLEIK >56D8_VH (SEQ ID NO: 110)QVQLVQSGAEVKKPGASVKVSCKASGYTFTMNSIDWVRQAPGQGLEWMGRIDPEEGGTKYAQKFQGRVTFTRDTSTSTAYMELSSLRSDDTAVYYCARVDDYYLGYDYWGQGTQVTVSS >56D8_VK (SEQ ID NO: 111)DIVMTQSPDSLTASLGERVTINCKSSQSVLFSSNQKNYLAWYQQKPGQSPKLLIYWASIRESGVPDRFSGSGSGTDFTLTISSLQPEDVAVYYCQQGYSFPYSFGQGTRLEIR >56B1_VH (SEQ ID NO: 112)EVQLVQPGAEVKKPGASVKVSCKASGYTFTMNSIDWVRQAPGQGLEWMGRIDPEEGGTKYAQKFQGRVTFTRDTSTSTAYVELSSLRSDDTAVYYCARVDDYYLGYDYWGQGTLVTVSS >56B1_VK (SEQ ID NO: 113)DIVMTQSPDSLAVSEGERVTINCKSSQSVLFSSNQKNYLAWYQQKPGQSPRLLIYWASIRESGVPDRFSGSGSATDFTLTISSLQAEDVAVYYCQQGYSFPYSFGQGTRLEIR >56E9_VH (SEQ ID NO: 114)QVQLVQPGVEVKKPGASVKVSCKASGYTFTMNSIDWVRQAPGQGLEWMGRIDPEEGGTKYAQKFQGRVTFTADTSTSTAYMELSSLRSDDTAVYYCARVDDYYLGYDYWGQGTQVTVSS >56E9_VK (SEQ ID NO: 115)DIVMTQSPTSVAVSLGERATINCKSSQSVLFSSNQKNYLAWYQQKPGQPPRLLIYWASIRESGVPDRFSGSGSGTDFTLTISSLQPEDVAVYYCQQGYSFPYSFGQGTRLEIR >56E5_VH (SEQ ID NO: 116)QVQLVQPGAEVKKPGASVKVSCKASGYTFTMNSIDWVRQAPGQGLEWMGRIDPEEGGTKYAQKFQGRVTFTADTSTSTAYVELNSLRSEDTAVYYCARVDDYYLGYDYWGQGTQVTVSS >56E5_VK (SEQ ID NO: 117)DIVMTQSPDSLAVSLGEKVTINCKSSQSVLFSSNQKNYLAWYQQRPGQPPKLLIYWASIRESGVPDRFSGSGSATDFTLTISSLQPEDVAVYYCQQGYSFPYSFGQGTRLEIK >56E1_VH (SEQ ID NO: 118)QVQLVQPGAELRNPGASVKVSCKASGYTFTMNSIDWVRQAPGQGLEWMGRIDPEEGGTKYAQKFQGRVTMTRDTSTSTAYMELSSLRSEDTAVYYCARVDDYYLGYDYWGQGTQVTVSS >56E1_VK (SEQ ID NO: 119)DIVMTQTPDSLAVSAGERVTINCKSSQSVLFSSNQKNYLAWYQQKPGQSPKLLIYWASIRESGVPDRFSGSGSGTDFTLTISSLQPEDVTVYYCQQGYSFPYSFGQGTRLEIK >56G5_VH (SEQ ID NO: 120)QVQLVQPGAEVKKPGASVKVSCKASGYIFTMNSIDWVRQAPGQGLEWMGRIDPEEGGTKYAQKFQGRVTMTADTSTSTAYMELNSLRSEDTAVYYCARVDDYYLGYDYWGQGTLVTVSS >56G5_VK (SEQ ID NO: 121)DIVMTQTPTSLAPSAGERATINCKSSQSVLFSSNQKNYLAWYQQKPGQPPKLLIYWASIRESGVPDRFSGSGSATDFTLTISSLQPEDVAVYYCQQGYSF PYSFGSGTRLEIK

TABLE 15 Nucleotide sequences encoding heavy and light chainvariable domains of germlined variants of 48A2 >56F3_VH (SEQ ID NO: 122)GAGGTCCAGCTGGTGCAGCCAGGGGCGGAAGTGAAAAAACCTGGGGCATCAGTGAAGGTCTCCTGCAAGGCTTCTGGATACATCTTCACCATGAACTCAATAGACTGGGTGCGACAGGCCCCTGGACAAGGGCTTGAGTGGATGGGAAGAATTGACCCTGAAGAGGGTGGCACAAAGTATGCACAGAAGTTCCAGGGCAGAGTCACCATGACTGCAGACACGTCCACCAGCACAGCCTACATGGAGCTGAGCAGTCTGAGATCTGACGACACGGCCGTGTATTACTGTGCGAGAGTAGATGACTATTACCTTGGGTATGACTACTGGGGCCAGGGGACCCAGGTCACCGTCTCCTCA >56F3_VK (SEQ ID NO: 123)GATATTGTGATGACCCAGAGCCCCGATTCCTTGGCAGCGTCTTTAGGAGAACGTGTGACCATCAATTGTAAGTCCAGCCAGAGTGTGTTATTCAGCTCCAACCAGAAAAACTACTTAGCTTGGTACCAGCAGAGACCGGGACAGTCTCCTAAGCTGCTCATCTACTGGGCTTCCATCCGAGAATCGGGGGTTCCTGATCGATTCAGCGGCAGTGGGTCCGGCACAGATTTCACGCTAACCATCAGCTCTCTTCAGGCTGAAGACGTGGCAGTATATTACTGCCAGCAGGGTTATAGTTTTCCATATAGTTTCGGCAGTGGGACCAGGCTCGAGATCAAA >56D8_VH (SEQ ID NO: 124)CAGGTCCAGCTGGTGCAGTCTGGGGCGGAAGTGAAAAAACCTGGGGCATCAGTGAAGGTCTCCTGCAAGGCTTCTGGATACACCTTCACCATGAACTCAATAGACTGGGTGCGAGAGGCCCCTGGACAAGGGCTTGAGTGGATGGGAAGAATTGACCCTGAAGAGGGTGGCACAAAGTATGCACAGAAGTTCCAGGGCAGAGTCACCTTCACTCGAGACACGTCCACCAGCACAGCCTACATGGAGCTGAGCAGTCTGAGATCTGACGACACGGCCGTGTATTACTGTGCGAGAGTAGATGACTATTACCTTGGGTATGACTACTGGGGCCAGGGGACCCAGGTCACCGTCTCCTCA >56D8_VK (SEQ ID NO: 125)GATATTGTGATGACCCAGAGCCCCGATTCCTTGACAGCGTCTTTAGGAGAACGTGTGACCATCAATTGTAAGTCCAGCCAGAGTGTGTTATTCAGCTCCAACCAGAAAAACTACTTAGCTTGGTACCAGCAGAAACCGGGACAGTCTCCTAAGCTGCTCATCTACTGGGCTTCCATCCGAGAATCGGGGGTTCCTGATCGATTCAGCGGCAGTGGGTCCGGCACAGATTTCACGCTAACCATCAGCTCTCTTCAGCCTGAAGACGTGGCAGTATATTACTGCCAGCAGGGTTATAGTTTTCCATATAGTTTCGGCCAGGGCACCAGGCTCGAGATCAGA >56B1_VH (SEQ ID NO: 126)GAGGTCCAGCTGGTGCAGCCAGGGGCGGAAGTGAAAAAACCTGGGGCATCAGTGAAGGTCTCCTGCAAGGCTTCTGGATACACCTTCACCATGAACTCAATAGACTGGGTGCGAGAGGCCCCTGGACAAGGGCTTGAGTGGATGGGAAGAATTGACCCTGAAGAGGGTGGCACAAAGTATGCACAGAAGTTCCAGGGCAGAGTCACCTTCACTCGAGACACGTCCACCAGCACAGCCTACGTGGAGCTGAGCAGTCTGAGATCTGACGACACGGCCGTGTATTACTGTGCGAGAGTAGATGACTATTACCTTGGGTATGACTACTGGGGCCAGGGGACCCTGGTCACCGTCTCCTCA >56B1_VK (SEQ ID NO: 127)GATATTGTGATGACCCAGAGCCCCGATTCCTTGGCAGTGTCTGAAGGAGAACGTGTGACCATCAATTGTAAGTCCAGCCAGAGTGTGTTATTCAGCTCCAACCAGAAAAACTACTTAGCTTGGTACCAGCAGAAACCGGGACAGTCTCCTAGGCTGCTCATCTACTGGGCTTCCATCCGAGAATCGGGGGTTCCTGATCGATTCAGCGGCAGTGGGTCCGCCACAGATTTCACGCTAACCATCAGCTCTCTTCAGGCTGAAGACGTGGCAGTATATTACTGCCAGCAGGGTTATAGTTTTCCATATAGTTTCGGCCAGGGGACCAGGCTCGAGATCAGA >56E9_VH (SEQ ID NO: 128)CAGGTCCAGCTGGTGCAGCCAGGGGTGGAAGTGAAAAAACCTGGGGCATCAGTGAAGGTCTCCTGCAAGGCTTCTGGATACACCTTCACCATGAACTCAATAGACTGGGTGCGACAGGCCCCTGGACAAGGGCTTGAGTGGATGGGAAGAATTGACCCTGAAGAGGGTGGCACAAAGTATGCACAGAAGTTCCAGGGCAGAGTCACCTTCACTGCAGACACGTCCACCAGCACAGCCTACATGGAGCTGAGCAGTCTGAGATCTGACGACACGGCCGTGTATTACTGTGCGAGAGTAGATGACTATTACCTTGGGTATGACTACTGGGGCCAGGGGACCCAGGTCACCGTCTCCTCA >56E9_VK (SEQ ID NO: 129)GATATTGTGATGACCCAGAGCCCCACCTCCGTGGCAGTGTCTTTAGGAGAACGTGCGACCATCAATTGTAAGTCCAGCCAGAGTGTGTTATTCAGCTCCAACCAGAAAAACTACTTAGCTTGGTACCAGCAGAAACCGGGACAGCCTCCTAGGCTGCTCATCTACTGGGCTTCCATCCGAGAATCGGGGGTTCCTGATCGATTCAGCGGCAGTGGGTCCGGCACAGATTTCACGCTAACCATCAGCTCTCTTCAGCCTGAAGACGTGGCAGTATATTACTGCCAGCAGGGTTATAGTTTTCCATATAGTTTCGGCCAGGGGACCAGGCTCGAGATCAGA >56E5_VH (SEQ ID NO: 130)CAGGTCCAGCTGGTGCAGCCAGGGGCGGAAGTGAAAAAACCTGGGGCATCAGTGAAGGTCTCCTGCAAGGCTTCTGGATACACCTTCACCATGAACTCAATAGACTGGGTGCGACAGGCCCCTGGACAAGGGCTTGAGTGGATGGGAAGAATTGACCCTGAAGAGGGTGGCACAAAGTATGCACAGAAGTTCCAGGGCAGAGTCACCTTCACTGCAGACACGTCCACCAGCACAGCCTACGTGGAGCTGAACAGTCTGAGATCTGAGGACACGGCCGTGTATTACTGTGCGAGAGTAGATGACTATTACCTTGGGTATGACTACTGGGGCCAGGGGACCCAGGTCACCGTCTCCTCA >56E5_VK (SEQ ID NO: 131)GATATTGTGATGACCCAGAGCCCCGATTCCTTGGCAGTGTCTTTAGGAGAAAAGGTGACCATCAATTGTAAGTCCAGCCAGAGTGTGTTATTCAGCTCCAACCAGAAAAACTACTTAGCTTGGTACCAGCAGAGACCGGGACAGCCTCCTAAGCTGCTCATCTACTGGGCTTCCATCCGAGAATCGGGGGTTCCTGATCGATTCAGCGGCAGTGGGTCCGCCACAGATTTCACGCTAACCATCAGCTCTCTTCAGCCTGAAGACGTGGCAGTATATTACTGCCAGCAGGGTTATAGTTTTCCATATAGTTTCGGCCAGGGGACCAGGCTCGAGATCAAA >56E1_VH (SEQ ID NO: 132)GAGGTCCAGCTGGTGCAGCCAGGGGCGGAACTGAGAAACCCTGGGGCATCAGTGAAGGTCTCCTGCAAGGCTTCTGGATACACCTTCACCATGAACTCAATAGACTGGGTGCGACAGGCCCCTGGACAAGGGCTTGAGTGGATGGGAAGAATTGACCCTGAAGAGGGTGGCACAAAGTATGCACAGAAGTTCCAGGGCAGAGTCACCATGACTCGAGACACGTCCACCAGCACAGCCTACATGGAGCTGAGCAGTCTGAGATCTGAGGACACGGCCGTGTATTACTGTGCGAGAGTAGATGACTATTACCTTGGGTATGACTACTGGGGCCAGGGGACCCAGGTCACCGTCTCCTCA >56E1_VK (SEQ ID NO: 133)GATATTGTGATGACCCAGACCCCCGATTCCTTGGCAGTGTCTGCAGGAGAACGTGTGACCATCAATTGTAAGTCCAGCCAGAGTGTGTTATTCAGCTCCAACCAGAAAAACTACTTAGCTTGGTACCAGCAGAAACCGGGACAGTCTCCTAAGCTGCTCATCTACTGGGCTTCCATCCGAGAATCGGGGGTTCCTGATCGATTCAGCGGCAGTGGGTCCGGCACAGATTTTACGCTAACCATCAGCTCTCTTCAGCCTGAAGACGTGACAGTATATTACTGCCAGCAGGGTTATAGTTTTCCATATAGTTTCGGCCAGGGGACCAGGCTCGAGATCAAA >56G5_VH (SEQ ID NO: 134)CAGGTCCAGCTGGTGCAGCCAGGGGCGGAAGTGAAAAAACCTGGGGCATCAGTGAAGGTCTCCTGCAAGGCTTCTGGATACATCTTCACCATGAACTCAATAGACTGGGTGCGACAGGCCCCTGGACAAGGGCTTGAGTGGATGGGAAGAATTGACCCTGAAGAGGGTGGCACAAAGTATGCACAGAAGTTCCAGGGCAGAGTCACCATGACTGCAGACACGTCCACCAGCACAGCCTACATGGAGCTGAACAGTCTGAGATCTGAGGACACGGCCGTGTATTACTGTGCGAGAGTAGATGACTATTACCTTGGGTATGACTACTGGGGCCAGGGGACCCTGGTCACCGTCTCCTCA >56G5_VK (SEQ ID NO: 135)GATATTGTGATGACCCAGACCCCCACCTCCTTGGCACCGTCTGCAGGAGAACGTGCGACCATCAATTGTAAGTCCAGCCAGAGTGTGTTATTCAGCTCCAACCAGAAAAACTACTTAGCTTGGTACCAGCAGAAACCGGGACAGCCTCCTAAGCTGCTCATCTACTGGGCTTCCATCCGAGAATCGGGGGTTCCTGATCGATTCAGCGGCAGTGGGTCCGCCACAGATTTCACGCTAACCATCAGCTCTCTTCAGCCTGAAGACGTGGCAGTATATTACTGCCAGCAGGGTTATAGTTTTCCATATAGTTTCGGCAGTGGGACCAGGCTCGAGATCAAA

Example 22: Germlining of 36C4 does not Lead to Loss in Potency

For 36C4, four germlined clones (55A12-54E, 53E2-54E, 53E3, 53A11) werefurther characterized for agonistic and antagonistic properties in theA549 phosphorylation assay as described in Example 9. As shown in FIG.20A, there were no increased agonistic properties of the germlined mAbs55A12-54E and 53E2-54E as compared to the parental 36C4. The germlinedvariants 53E3 and 53A11 showed the same results. The antagonistic effectof the germlined mAbs were not significantly altered either as shown inFIG. 20B, exemplified by 55A12-54E and 53E2-54E.

Example 23: PBS Stability of Germlined 36C4 mAbs

Stability of 3 mg/ml IgG in PBS+0.02% Tween-80 was investigated at days0-1-7-14-28-56 after storage at 4° C., RT and 37° C. All samples weretested for their potency by Surface Plasmon Resonance investigatingbinding to coupled c-Met (15,000-17,000 RU) and determining the slopebetween 100-130 seconds at a flow rate of 30 μl/min. The percentage offunctional mAbs was calculated based on the reference (germlined mAbsstored at −20° C.). FIG. 21 shows that there was not significant loss offunctionality after 56 days incubation at the different temperatures andthere did not seem to be a significant difference between the fourgermlined mAbs.

Example 24: Thermotolerance of Germlined 36C4 and 48A2 mAbs

The thermotolerance of germlined 36C4 and 48A2 mAbs was investigated byincubation at different temperatures for 1 h before the samples (0.5μg/ml) were run on CM-5 chip coupled with 15,000-17,000 RU Decoy c-Metand the slope determining the slope between 100-130 seconds at a flowrate of 30 μl/min. The percentage of functional mAbs was calculatedbased on the reference (incubated at 4° C.) set to 100%. As shown inFIG. 22A, the melting temperatures (EC50) of the germlined mAbs was67.2° C. for 36C4, 67.1° C. for 55A12-54E, 66.1° C. for 53E2-54E, 68.2°C. for 53E3 and 65.5° C. for 53A11. For 48A2, germlined mAb 56F3, therewas a significant improvement in melting temperature from 65.4 to 71.1°C. (FIG. 22B).

Example 25: Determination of c-Met Peptide Binding Sites of mAbs 36C4and 48A2 Using Human-Llama Chimeric c-Met

To further define the amino acid (aa) stretches of c-Met to which themAbs 36C4 and 48A2 were binding, chimeric c-Met constructs containingapproximately 20-300 aa exchanges from human to llama c-Met wereprepared using PCR amplifications and ligations into the human c-Metcontaining vector with a Flag and a strep tag. FIG. 23A shows thechimeric c-Met constructs used for peptide mapping of 36C4 binding tothe SEMA domain, whereas FIG. 23B show the chimeric c-Met constructs forthe peptide mapping of 48A2 binding to the PSI-IPT1 domain

The llama-human c-Met chimeras were produced in HEK293E cells andpurified using strep-tactin sepharose HP (2-3 h at 11° C.) beforewashing of unbound proteins. The bound proteins were eluted with 2.5 mMdesthiobiotin pH 8.2 and fractions of 1.5 ml were collected. Proteinconcentration was determined by Nanodrop. Protein was quality controlledby SDS-PAGE.

An ELISA was run to investigate the binding of the mAbs to the differentchimeras. 2 μg/m136C4 or 48A2 were immobilized and, after blocking, thec-Met chimeras were added and revealed with 1/10,000 streptavidin-HRP(ELISA in Table 16).

Surface Plasmon Resonance (SPR) was also used to investigate the bindingof the mAbs to the different llama-human c-Met chimeras. 3000 RU of36C4, 48A2 and HGF were coupled on a CM-5 chip in 10 mM NaAc (pH4.5). 60μl of a 10 μg/ml solution of the different c-Met chimeras was run overthe chip at a flow rate of 30 μl/min and the association for 2 min wasevaluated. The chip was regenerated with 20 mM NaOH and 1 M NaCl.

Table 16 show the chimeras with the human c-Met and the amino acids(starting with aa E in the mature protein of the human c-Met) that wereexchanged with the llama c-Met peptides and the binding results usingPlasmon resonance and ELISA. The results were consistent and showed that36C4 binding stops at aa 199, indicating a recognition site within aa98-199 of human c-Met. This is the part of the SEMA domain that containsthe HGF β-chain binding site, as shown in the crystal structurepublished by Stamos et al, (EMBO J, 2004).

The 48A2 mAb bound to aa 523-633 of human c-Met, which covers both partof the PSI and the IPT1 domains indicating recognition of aconformational epitope in both domains.

Western Blot with c-Met run under reducing conditions was used toinvestigate if 36C4 and 48A2 bound linear or conformational epitopes. Nobinding was observed for 36C4 or 48A2 indicating recognition of aconformational epitope (data not shown), which was confirmed with thechimeric c-Met proteins.

TABLE 16 Llama-human c-Met chimeras and binding results of 36C4 and 48A2measured by SPR and ELISA ELISA SPR (EC₅₀ ng/ml) Chimera HGF 36C4 48A236C4 48A2 LS1 (aa1-98) + + + 68 31 LS2 (aa1-199) + − + — 34 LS3(aa1-287) + − + — 50 LS4 (aa1-348) + − + — 70 LS5 (aa1-448) + − + — 50LP6 (aa497-909) + + − 50 — LP7* (aa523-909) + + − 55 — Ll8(aa540-909) + + +/− 47 >40 Ll9 (aa572-909) + + +/− 47 >40 Ll10(aa608-909) + + +/− 47 >40 Ll11 (aa634-909) + + + 45 42 LMet − − − — —HMet + + + 60 45 *T737I

Sequence of the human c-Met peptide recognized by mAb 36C4 (aa98-199)SEQ ID NO: 181 VDTYYDDQLISCGSVNRGTCQRHVFPHNHTADIQSEVHCIFSPQIEEPSQCPDCVVSALGAKVLSSVKDRFINFFVGNTINSSYFPDHPLHSISVRRL KETKSequence of the human c-Met peptide recognized by mAb 48A2 (aa523-633)SEQ ID NO: 136 RSEECLSGTWTQQICLPAIYKVFPNSAPLEGGTRLTICGWDFGFRRNNKFDLKKTRVLLGNESCTLTLSESTMNTLKCTVGPAMNKHFNMSIIISNGH GTTQYSTFSYVDP

Example 26: Down-Regulation of Total c-Met by the mAbs on MKN-45 Cells

The amount of total cMet present on the surface of MKN-45 cells afterincubation with the mAbs was measured using Flow cytometry.

25,000 MKN-45 cells/well in a 96-well plate were seeded and incubatedfor 24 h at 37° C., 5% CO₂. The cells were serum starved for 8 h beforeaddition of the mAbs and HGF at 10 or 1 μg/ml diluted in serum-freemedium and in triplicates. Murine 5D5 antibody and HGF were included ascontrols for down-regulation of the total c-Met. The negative control isan irrelevant IgG1 mAb produced in the same way as the 36C4 and 48A2.

The cells were washed with PBS and 50 μl/well of enzyme-free celldissociation solution was added and incubated for 15 min at 37° C. Thecells were collected in a FACS plate and 100 μl binding buffer (PBS+1%BSA) was added before centrifugation at 2000 rpm for 3 min. The cellswere kept at 4° C. from this point on. The cells were washed twice withbinding buffer and then 2.5 μg/ml mouse anti-c-Met antibody (R&DSystems) added. The cells were then incubated for 1 h with shaking at 4°C., followed by washing twice with the binding buffer. APC-conjugatedgoat anti-mouse antibody (Jackson Lab) was added at a concentration of1/500 and the cells incubated for 1 h with shaking. The cells were thenwashed with binding buffer and read on a FACS Calibur. 2000 events werecollected and the down-regulation was expressed as a percentage of thedown-regulation in the medium control.

The mAbs 36C4 and 48A2 do not induce significant down-regulation ofc-Met on the surface of MKN-45 cells compared to either 5D5 or HGF (seeFIG. 24), both of which induce 50-60% down-regulation of cMet afterincubation over night.

The invention claimed is:
 1. A monoclonal antibody or antigen bindingfragment thereof which specifically binds human c-Met protein, theantibody or antigen binding fragment comprising a heavy chain variable(VH) domain comprising CDRH1, CDRH2, and CDRH3 regions, and a lightchain variable (VL) domain comprising CDRL1, CDRL2, and CDRL3 regions,wherein the CDRH1, CDRH2, CDRH3, CDRL1, CDRL2, and CDRL3 regionscomprise the amino acid sequences set forth in SEQ ID NOs: 13, 14, 15,22, 23, and 24, respectively.
 2. The antibody or antigen bindingfragment of claim 1, wherein the VH domain comprises the amino acidsequence set forth in SEQ ID NO:
 49. 3. The antibody or antigen bindingfragment of claim 1, wherein the VL domain comprises the amino acidsequence set forth in SEQ ID NO:
 52. 4. The antibody or antigen bindingfragment of claim 1, wherein the VH domain comprises the amino acidsequence set forth in SEQ ID NO: 49, and the VL domain comprises theamino acid sequence set forth in SEQ ID NO:
 52. 5. The antibody orantigen binding fragment of claim 1, wherein the VH and VL domains arefused to constant domains of a human antibody.
 6. The antibody orantigen binding fragment of claim 5, wherein the human antibody is humanIgG1.
 7. The antibody or antigen binding fragment of claim 1, whereinthe antibody or antigen binding fragment is humanized.
 8. The antibodyaccording to claim 1, which is a non-fucosylated IgG.
 9. Animmunoconjugate comprising the antibody or antigen binding fragment ofclaim 1 conjugated to a cytotoxic agent, cytostatic agent, toxin, orradionuclide.
 10. A pharmaceutical composition comprising an antibody orantigen binding fragment according to claim 1 and a pharmaceuticallyacceptable carrier or excipient.